Merge pull request #1069 from MBombeck/fix/v1397-units

One unit system: every surface follows the reader's glucose and metric/imperial preference

src/components/charts/workout-elevation-chart.tsx

@@ -11,6 +11,11 @@ import {
 } from "recharts";
 
 import { useTranslations } from "@/lib/i18n/context";
+import { useUnitDisplay } from "@/hooks/use-unit-display";
+import {
+  applyDisplayTransform,
+  getQuantityTransform,
+} from "@/lib/measurements/display-transform";
 
 /**
  * Workout elevation profile — a small cumulative-distance / altitude
@@ -30,7 +35,15 @@ export function WorkoutElevationChart({
   points: WorkoutElevationPoint[];
 }) {
   const { t } = useTranslations();
-  const data = points.map((p) => ({ km: p.distanceM / 1000, alt: p.altitude }));
+  const { preference } = useUnitDisplay();
+  // Distance along the route in km or mi, altitude in m or ft — the same
+  // registry the stat tiles read, so the axis and the tiles agree.
+  const distance = getQuantityTransform("distance", preference);
+  const elevation = getQuantityTransform("elevation", preference);
+  const data = points.map((p) => ({
+    dist: applyDisplayTransform(p.distanceM, distance),
+    alt: applyDisplayTransform(p.altitude, elevation),
+  }));
 
   return (
     <div className="h-24 w-full" data-slot="workout-elevation-chart">
@@ -57,7 +70,7 @@ export function WorkoutElevationChart({
             opacity={0.4}
           />
           <XAxis
-            dataKey="km"
+            dataKey="dist"
             type="number"
             domain={[0, "dataMax"]}
             tick={{ fontSize: 10, fill: "var(--muted-foreground)" }}
@@ -80,9 +93,11 @@ export function WorkoutElevationChart({
               borderRadius: "0.5rem",
               fontSize: "0.875rem",
             }}
-            labelFormatter={(km) => `${Number(km).toFixed(2)} km`}
+            labelFormatter={(d) =>
+              `${Number(d).toFixed(2)} ${distance.displayUnit}`
+            }
             formatter={(value) => [
-              `${Math.round(Number(value))} m`,
+              `${Math.round(Number(value))} ${elevation.displayUnit}`,
               t("insights.workouts.detail.elevationTitle"),
             ]}
           />

src/components/clinician/__tests__/clinician-view.test.tsx

@@ -225,6 +225,49 @@ describe("<ClinicianView>", () => {
     expect(html).not.toContain(">WEIGHT<");
   });
 
+  it("prints every measurement group with its unit", () => {
+    const html = render(
+      makeReport({
+        stats: {
+          WEIGHT: { avg: 80, min: 78, max: 82, count: 12, latest: 79 },
+          // Per-night asleep minutes; the report reads them in hours.
+          SLEEP_DURATION: {
+            avg: 450,
+            min: 420,
+            max: 480,
+            count: 7,
+            latest: 450,
+          },
+        },
+      }),
+    );
+    expect(html).toContain("latest 79 kg (avg 80 kg, range 78–82 kg)");
+    expect(html).toContain("latest 7.5 h (avg 7.5 h, range 7–8 h)");
+  });
+
+  it("shows glucose in the record owner's unit, never raw mg/dL", () => {
+    const html = render(
+      makeReport({
+        glucoseUnit: "mmol/L",
+        stats: {
+          BLOOD_GLUCOSE: { avg: 108, min: 90, max: 126, count: 9, latest: 99 },
+        },
+        glucoseStats: {
+          FASTING: { avg: 99, min: 90, max: 108, count: 5, latest: 95 },
+        },
+      }),
+    );
+    // 99 mg/dL = 5.5 mmol/L, 108 = 6.0, 90 = 5.0, 126 = 7.0, 95 = 5.3.
+    expect(html).toContain(
+      "latest 5.5 mmol/L (avg 6 mmol/L, range 5–7 mmol/L)",
+    );
+    expect(html).toContain(
+      "latest 5.3 mmol/L (avg 5.5 mmol/L, range 5–6 mmol/L)",
+    );
+    expect(html).not.toContain("mg/dL");
+    expect(html).not.toContain("latest 99");
+  });
+
   it("omits the wellness card when there are no scores", () => {
     const html = render(makeReport({ wellnessScores: [] }));
     expect(html).not.toContain("Wellness scores");

src/components/clinician/report-sections.tsx

@@ -15,6 +15,11 @@
  */
 import type { MeasurementType } from "@/generated/prisma/client";
 import type { DoctorReportData } from "@/lib/doctor-report-data";
+import {
+  reportStatUnit,
+  reportStatValue,
+} from "@/lib/doctor-report/stat-display";
+import { convertGlucose, resolveGlucoseUnit } from "@/lib/glucose";
 import { MEASUREMENT_TYPE_LABEL_KEYS } from "@/lib/measurements/type-label-keys";
 import {
   isReportLeafId,
@@ -212,6 +217,13 @@ export function MeasurementGroups({
 
   if (groups.length === 0) return null;
 
+  // The same unit and the same number the PDF prints for the row: SI for
+  // mass, length and temperature, the owner's unit for glucose, hours for
+  // sleep. A clinician must never read a figure without knowing its unit.
+  const glucoseUnit = resolveGlucoseUnit(report.glucoseUnit ?? null);
+  const show = (type: string, value: number) =>
+    fmtNum(reportStatValue(type, value, glucoseUnit));
+
   return (
     <>
       {groups.map((group) => (
@@ -224,11 +236,11 @@ export function MeasurementGroups({
             <StatRow
               key={type}
               label={t(MEASUREMENT_TYPE_LABEL_KEYS[type])}
-              value={t("clinicianView.statSummary", {
-                latest: fmtNum(stat!.latest),
-                avg: fmtNum(stat!.avg),
-                min: fmtNum(stat!.min),
-                max: fmtNum(stat!.max),
+              value={statSummary(t, reportStatUnit(type, glucoseUnit, t), {
+                latest: show(type, stat!.latest),
+                avg: show(type, stat!.avg),
+                min: show(type, stat!.min),
+                max: show(type, stat!.max),
               })}
             />
           ))}
@@ -238,6 +250,20 @@ export function MeasurementGroups({
   );
 }
 
+/**
+ * "latest 79 kg (avg 80 kg, range 78–82 kg)". A type with no unit (a score, a
+ * count) keeps the unit-less sentence rather than printing a dangling space.
+ */
+function statSummary(
+  t: Translate,
+  unit: string,
+  values: { latest: number; avg: number; min: number; max: number },
+): string {
+  return unit
+    ? t("clinicianView.statSummaryWithUnit", { ...values, unit })
+    : t("clinicianView.statSummary", values);
+}
+
 /**
  * Per-context glucose stats. The heading used to read "Lab values", which was
  * the wrong name for it even before the record's actual lab results reached
@@ -258,6 +284,9 @@ export function GlucoseSection({
   const entries = Object.entries(report.glucoseStats).filter(
     ([, s]) => s.count > 0,
   );
+  // Stored in mg/dL; shown in the record owner's unit, as the PDF shows it.
+  const glucoseUnit = resolveGlucoseUnit(report.glucoseUnit ?? null);
+  const show = (value: number) => fmtNum(convertGlucose(value, glucoseUnit));
   return (
     <LeafSection
       t={t}
@@ -270,11 +299,11 @@ export function GlucoseSection({
         <StatRow
           key={ctx}
           label={t(`clinicianView.glucose.${ctx}`)}
-          value={t("clinicianView.statSummary", {
-            latest: fmtNum(s.latest),
-            avg: fmtNum(s.avg),
-            min: fmtNum(s.min),
-            max: fmtNum(s.max),
+          value={statSummary(t, glucoseUnit, {
+            latest: show(s.latest),
+            avg: show(s.avg),
+            min: show(s.min),
+            max: show(s.max),
           })}
         />
       ))}

src/components/cycle/__tests__/cycle-phase-crosstab.test.tsx

@@ -6,12 +6,17 @@ import { renderToStaticMarkup } from "react-dom/server";
 // QueryClient, so mock the hook to a real metric-preference implementation —
 // metric is the identity on values and yields the canonical display symbols,
 // so the assertions below (kg, °C, unchanged numbers) hold.
+const reader = vi.hoisted(() => ({
+  glucoseUnit: "mg/dL" as "mg/dL" | "mmol/L",
+}));
+
 vi.mock("@/hooks/use-unit-display", async () => {
   const dt = await import("@/lib/measurements/display-transform");
   const forType = (t: string) => dt.getDisplayTransform(t, "metric");
   return {
     useUnitDisplay: () => ({
       preference: "metric" as const,
+      glucoseUnit: reader.glucoseUnit,
       transformFor: forType,
       toDisplay: (t: string, v: number) =>
         dt.applyDisplayTransform(v, forType(t)),
@@ -107,4 +112,26 @@ describe("<CyclePhaseCrosstab>", () => {
     const html = render(<CyclePhaseCrosstab rows={[unknown]} />);
     expect(html).not.toContain("undefined");
   });
+
+  it("states a glucose row in mmol/L for an mmol/L reader", () => {
+    reader.glucoseUnit = "mmol/L";
+    try {
+      const glucose: CyclePhaseCrosstabRow = {
+        ...row("bloodGlucose", "glucose"),
+        lutealAvg: 108,
+        follicularAvg: 90,
+        delta: 18,
+      };
+      const html = render(<CyclePhaseCrosstab rows={[glucose]} />);
+      // 18 mg/dL is 1.0 mmol/L; 108 / 90 mg/dL are 6.0 / 5.0 mmol/L.
+      expect(html).toContain("+1.0 mmol/L");
+      expect(html).toContain("6.0");
+      expect(html).not.toContain("mg/dL");
+      expect(render(<CyclePhaseHeadline headline={glucose} />)).toContain(
+        "mmol/L",
+      );
+    } finally {
+      reader.glucoseUnit = "mg/dL";
+    }
+  });
 });

src/components/cycle/cycle-phase-crosstab.tsx

@@ -1,7 +1,12 @@
 "use client";
 
 import { useTranslations } from "@/lib/i18n/context";
-import { useUnitDisplay } from "@/hooks/use-unit-display";
+import { useUnitDisplay, type UnitDisplay } from "@/hooks/use-unit-display";
+import {
+  applyDisplayTransform,
+  applyDisplayTransformDelta,
+  getReadingTransform,
+} from "@/lib/measurements/display-transform";
 import { cn } from "@/lib/utils";
 
 /**
@@ -88,8 +93,47 @@ function fmt(value: number, display: CyclePhaseCrosstabDisplay): string {
 const DISPLAY_TO_TYPE: Partial<Record<CyclePhaseCrosstabDisplay, string>> = {
   kg: "WEIGHT",
   celsius: "BODY_TEMPERATURE",
+  glucose: "BLOOD_GLUCOSE",
 };
 
+/**
+ * Unit symbol and conversions for one row, from the reader's preferences.
+ * Glucose follows the glucose unit (it used to print the mg/dL label from
+ * the bundle beside raw mg/dL values for every reader); weight and
+ * temperature follow metric/imperial; every other display keeps its bundle
+ * label and its raw value.
+ */
+function rowUnits(
+  display: CyclePhaseCrosstabDisplay,
+  unitDisplay: UnitDisplay,
+  t: (key: string) => string,
+): {
+  unit: string;
+  abs: (v: number) => number;
+  delta: (v: number) => number;
+} {
+  const type = DISPLAY_TO_TYPE[display];
+  if (!type) {
+    // Defensive: an unmapped display must never pass undefined to `t`
+    // (whose resolver does `key.split(".")`). Empty unit on a miss.
+    const unitKey = UNIT_KEY[display];
+    return {
+      unit: unitKey ? t(unitKey) : "",
+      abs: (v) => v,
+      delta: (v) => v,
+    };
+  }
+  const transform = getReadingTransform(type, {
+    system: unitDisplay.preference,
+    glucoseUnit: unitDisplay.glucoseUnit,
+  });
+  return {
+    unit: transform.displayUnit,
+    abs: (v) => applyDisplayTransform(v, transform),
+    delta: (v) => applyDisplayTransformDelta(v, transform),
+  };
+}
+
 const HEADLINE_KEY: Record<string, string> = {
   restingHeartRate: "cycle.insights.headline.restingHeartRate",
   heartRateVariability: "cycle.insights.headline.heartRateVariability",
@@ -120,11 +164,7 @@ export function CyclePhaseHeadline({
   const metricLabel = t(
     METRIC_LABEL_KEY[headline.metricKey] ?? headline.metricKey,
   );
-  // Defensive: an unmapped display must never pass undefined to `t` (whose
-  // resolver does `key.split(".")`). An empty unit is the honest degrade.
-  const mt = DISPLAY_TO_TYPE[headline.display];
-  const unitKey = UNIT_KEY[headline.display];
-  const unit = mt ? unitDisplay.unitFor(mt) : unitKey ? t(unitKey) : "";
+  const { unit, delta: deltaConv } = rowUnits(headline.display, unitDisplay, t);
   const up = headline.delta >= 0;
   const dir = t(
     up
@@ -134,12 +174,7 @@ export function CyclePhaseHeadline({
   const params = {
     metric: metricLabel,
     // A phase delta → factor-only conversion (no affine offset).
-    delta: fmt(
-      Math.abs(
-        mt ? unitDisplay.toDisplayDelta(mt, headline.delta) : headline.delta,
-      ),
-      headline.display,
-    ),
+    delta: fmt(Math.abs(deltaConv(headline.delta)), headline.display),
     unit,
     dir,
   };
@@ -175,15 +210,11 @@ export function CyclePhaseCrosstab({
           const metricLabel = t(
             METRIC_LABEL_KEY[row.metricKey] ?? row.metricKey,
           );
-          // Defensive: an unmapped display must never pass undefined to `t`
-          // (whose resolver does `key.split(".")`). Empty unit on a miss.
-          const mt = DISPLAY_TO_TYPE[row.display];
-          const unitKey = UNIT_KEY[row.display];
-          const unit = mt ? unitDisplay.unitFor(mt) : unitKey ? t(unitKey) : "";
-          const absConv = (v: number) =>
-            mt ? unitDisplay.toDisplay(mt, v) : v;
-          const deltaConv = (v: number) =>
-            mt ? unitDisplay.toDisplayDelta(mt, v) : v;
+          const {
+            unit,
+            abs: absConv,
+            delta: deltaConv,
+          } = rowUnits(row.display, unitDisplay, t);
           // `delta` = lutealAvg − follicularAvg: positive = the vital runs
           // higher in the luteal phase. The number stays NEUTRAL — higher is
           // good for steps but bad for resting HR, and this board is

src/components/illness/__tests__/illness-day-timeline-units.test.tsx

@@ -0,0 +1,70 @@
+/**
+ * A logged fever reads in the reader's temperature unit. The timeline and the
+ * day sheet printed a hardcoded °C, so an imperial account read its own
+ * fever in Celsius.
+ */
+import { describe, expect, it, vi } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+const account = vi.hoisted(() => ({
+  user: { unitPreference: "imperial", glucoseUnit: null } as Record<
+    string,
+    unknown
+  >,
+}));
+
+vi.mock("@/hooks/use-auth", () => ({
+  useAuth: () => ({ user: account.user, isAuthenticated: true }),
+  useAccountOnceMounted: () => account.user,
+}));
+
+vi.mock("@/hooks/use-record-capabilities", () => ({
+  useRecordCapabilities: () => ({ canManageDomain: () => true }),
+}));
+
+vi.mock("../use-illness", () => ({
+  useIllnessDayLogList: () => ({
+    isLoading: false,
+    isError: false,
+    data: {
+      dayLogs: [
+        {
+          id: "d1",
+          episodeId: "e1",
+          date: "2026-09-30",
+          functionalImpact: null,
+          feverC: 38.5,
+          symptoms: [],
+          note: null,
+          updatedAt: "2026-09-30T08:00:00.000Z",
+        },
+      ],
+    },
+  }),
+}));
+
+import { I18nProvider } from "@/lib/i18n/context";
+import { IllnessDayTimeline } from "../illness-day-timeline";
+
+function render(): string {
+  return renderToStaticMarkup(
+    <I18nProvider initialLocale="en">
+      <IllnessDayTimeline episodeId="e1" onLogDay={() => {}} />
+    </I18nProvider>,
+  );
+}
+
+describe("<IllnessDayTimeline> fever unit", () => {
+  it("shows the fever in °F for an imperial reader", () => {
+    account.user = { unitPreference: "imperial", glucoseUnit: null };
+    const html = render();
+    // 38.5 °C = 101.3 °F.
+    expect(html).toContain("Temperature: 101.3 °F");
+    expect(html).not.toContain("°C");
+  });
+
+  it("keeps °C for a metric reader", () => {
+    account.user = { unitPreference: "metric", glucoseUnit: null };
+    expect(render()).toContain("Temperature: 38.5 °C");
+  });
+});

src/components/illness/illness-day-timeline.tsx

@@ -19,6 +19,7 @@ import { Badge } from "@/components/ui/badge";
 import { Button } from "@/components/ui/button";
 import { Skeleton } from "@/components/ui/skeleton";
 import { useTranslations, useFormatters } from "@/lib/i18n/context";
+import { useUnitDisplay } from "@/hooks/use-unit-display";
 
 import { ILLNESS_SYMPTOM_CATALOG } from "./symptom-catalog";
 import { useIllnessDayLogList } from "./use-illness";
@@ -32,6 +33,7 @@ function symptomLabelKey(key: string): string | null {
 function DayLogRow({ log }: { log: IllnessDayLogDTO }) {
   const { t } = useTranslations();
   const fmt = useFormatters();
+  const { toDisplay, unitFor } = useUnitDisplay();
 
   return (
     <div className="border-border/60 space-y-2 border-l-2 pl-3">
@@ -72,7 +74,10 @@ function DayLogRow({ log }: { log: IllnessDayLogDTO }) {
 
       {log.feverC !== null ? (
         <p className="text-foreground text-sm">
-          {t("illness.timeline.fever", { value: fmt.number(log.feverC, 1) })}
+          {t("illness.timeline.fever", {
+            value: fmt.number(toDisplay("BODY_TEMPERATURE", log.feverC), 1),
+            unit: unitFor("BODY_TEMPERATURE"),
+          })}
         </p>
       ) : null}
 

src/components/illness/log-day-sheet.tsx

@@ -25,6 +25,7 @@ import { Label } from "@/components/ui/label";
 import { Textarea } from "@/components/ui/textarea";
 import { cn } from "@/lib/utils";
 import { useTranslations } from "@/lib/i18n/context";
+import { useUnitDisplay } from "@/hooks/use-unit-display";
 
 import { ILLNESS_SYMPTOM_CATALOG } from "./symptom-catalog";
 import { useIllnessDayLog, useUpsertDayLog } from "./use-illness";
@@ -140,6 +141,10 @@ export function LogDaySheet({
   onsetDate,
 }: LogDaySheetProps) {
   const { t } = useTranslations();
+  // The fever is stored in °C and typed in the reader's temperature unit:
+  // seeded through the transform, inverted on save.
+  const { toDisplay, fromDisplay, unitFor } = useUnitDisplay();
+  const feverUnit = unitFor("BODY_TEMPERATURE");
 
   // The day being logged — seeded from `date` (today), but the picker lets the
   // user backdate within [onset, today] for the retrospective journal.
@@ -178,7 +183,11 @@ export function LogDaySheet({
       new Map((dto?.symptoms ?? []).map((s) => [s.key, s.severity ?? null])),
     );
     setFunctionalImpact(dto?.functionalImpact ?? null);
-    setFever(dto?.feverC != null ? String(dto.feverC) : "");
+    setFever(
+      dto?.feverC != null
+        ? String(toDisplay("BODY_TEMPERATURE", dto.feverC))
+        : "",
+    );
     setNote(dto?.note ?? "");
   } else if (!open && lastFormKey !== null) {
     setLastFormKey(null);
@@ -213,7 +222,10 @@ export function LogDaySheet({
     const input: IllnessDayLogInput = {
       date: selectedDate,
       functionalImpact,
-      feverC: feverValue,
+      feverC:
+        feverValue == null
+          ? null
+          : Math.round(fromDisplay("BODY_TEMPERATURE", feverValue) * 100) / 100,
       symptoms: Array.from(symptoms.entries()).map(([key, severity]) => ({
         key,
         severity: severity ?? undefined,
@@ -333,7 +345,7 @@ export function LogDaySheet({
           summary={
             feverValue != null ? (
               <span className="text-muted-foreground text-xs">
-                {feverValue.toFixed(1)} °C
+                {feverValue.toFixed(1)} {feverUnit}
               </span>
             ) : null
           }
@@ -345,7 +357,7 @@ export function LogDaySheet({
             <Input
               id="illness-fever"
               inputMode="decimal"
-              placeholder="37.0"
+              placeholder={toDisplay("BODY_TEMPERATURE", 37).toFixed(1)}
               value={fever}
               onChange={(e) => setFever(e.target.value)}
               className="max-w-32"

src/components/insights/__tests__/trends-row.test.tsx

@@ -21,14 +21,40 @@ import { I18nProvider } from "@/lib/i18n/context";
 
 vi.mock("next/dynamic", () => ({
   default: () => {
-    const Stub = ({ title }: { title?: string }) => (
-      <div data-slot="trends-row-chart-stub">{title ?? "chart"}</div>
+    const Stub = ({
+      title,
+      unit,
+      valueScale,
+      valueOffset,
+    }: {
+      title?: string;
+      unit?: string;
+      valueScale?: number;
+      valueOffset?: number;
+    }) => (
+      <div
+        data-slot="trends-row-chart-stub"
+        data-unit={unit}
+        data-scale={valueScale}
+        data-offset={valueOffset}
+      >
+        {title ?? "chart"}
+      </div>
     );
     Stub.displayName = "TrendsRowChartStub";
     return Stub;
   },
 }));
 
+const account = vi.hoisted(() => ({
+  user: null as Record<string, unknown> | null,
+}));
+vi.mock("@/hooks/use-auth", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("@/hooks/use-auth")>()),
+  useAuth: () => ({ user: account.user, isAuthenticated: true }),
+  useAccountOnceMounted: () => account.user,
+}));
+
 import { TrendsRow } from "../trends-row";
 import type { DailyBriefing } from "@/lib/ai/schema";
 
@@ -306,4 +332,27 @@ describe("<TrendsRow>", () => {
     expect(html).toMatch(/data-metric="steps"/);
     expect(html).toContain('href="/insights/steps"');
   });
+
+  it("plots a transformed slot in the reader's unit, scale and offset included", () => {
+    account.user = { unitPreference: "imperial", glucoseUnit: null };
+    try {
+      const html = render(
+        <TrendsRow briefing={briefing(["weight", "distance", "body_temp"])} />,
+      );
+      expect(html).toContain('data-unit="lb"');
+      expect(html).toContain('data-unit="mi"');
+      expect(html).toContain('data-unit="°F"');
+      expect(html).toContain('data-offset="32"');
+      expect(html).not.toContain('data-unit="kg"');
+      expect(html).not.toContain('data-unit="km"');
+    } finally {
+      account.user = null;
+    }
+  });
+
+  it("plots distance in kilometres, scaled from metres, for a metric reader", () => {
+    const html = render(<TrendsRow briefing={briefing(["distance"])} />);
+    expect(html).toContain('data-unit="km"');
+    expect(html).toContain('data-scale="0.001"');
+  });
 });

src/components/insights/__tests__/workout-detail.test.tsx

@@ -1,4 +1,4 @@
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, vi } from "vitest";
 import { renderToStaticMarkup } from "react-dom/server";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 
@@ -16,6 +16,19 @@ import { WorkoutInsightCard } from "../workout-detail/insight-slot";
 import type { WorkoutDetailPayload } from "@/hooks/use-workouts";
 import type { RouteCoordinate } from "@/lib/workouts/route-svg";
 
+// The unit preference comes from the account payload; a mutable stub lets a
+// test switch the reader to imperial.
+const account = vi.hoisted(() => ({
+  user: { unitPreference: "metric", glucoseUnit: null } as Record<
+    string,
+    unknown
+  >,
+}));
+vi.mock("@/hooks/use-auth", () => ({
+  useAuth: () => ({ user: account.user, isAuthenticated: true }),
+  useAccountOnceMounted: () => account.user,
+}));
+
 /**
  * #67 — `<WorkoutDetail*>` unit tests over the split `workout-detail/`
  * directory. Each primitive runs through SSR with a canonical fixture;
@@ -149,6 +162,44 @@ describe("<WorkoutDetailStats>", () => {
     expect(html).toContain("148 bpm");
   });
 
+  it("states distance, pace, elevation and the average line in imperial units", () => {
+    account.user = { unitPreference: "imperial", glucoseUnit: null };
+    try {
+      const html = render(
+        <WorkoutDetailStats
+          workout={{
+            ...FIXTURE,
+            sportContext: {
+              count: 8,
+              avgDurationSec: 2040,
+              avgDistanceM: 5800,
+              avgAvgHr: 148,
+            },
+          }}
+        />,
+      );
+      // 5200 m = 3.23 mi; 1800 s over it = 9:17 per mile; 12.5 m = 41.0 ft.
+      expect(html).toContain("3.23 mi");
+      expect(html).toContain("9:17 /mi");
+      expect(html).toContain("41.0 ft");
+      // The sport-average line: 5800 m = 3.60 mi.
+      expect(html).toContain("3.60 mi");
+      expect(html).not.toContain(" km");
+      expect(html).not.toContain("/km");
+      const header = render(<WorkoutDetailHeader workout={FIXTURE} />);
+      expect(header).toContain("3.23 mi");
+    } finally {
+      account.user = { unitPreference: "metric", glucoseUnit: null };
+    }
+  });
+
+  it("keeps kilometres, minutes per km and metres for a metric reader", () => {
+    const html = render(<WorkoutDetailStats workout={FIXTURE} />);
+    expect(html).toContain("5.20 km");
+    expect(html).toContain("5:46 /km");
+    expect(html).toContain("12.5 m");
+  });
+
   it("hides the average line for a lone session", () => {
     const lone: WorkoutDetailPayload = {
       ...FIXTURE,

src/components/insights/__tests__/workout-list.test.tsx

@@ -1,10 +1,23 @@
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, vi } from "vitest";
 import { renderToStaticMarkup } from "react-dom/server";
 
 import { I18nProvider } from "@/lib/i18n/context";
 import { WorkoutList } from "../workout-list";
 import type { WorkoutListEntry } from "@/hooks/use-workouts";
 
+// The unit preference comes from the account payload; a mutable stub lets a
+// test switch the reader to imperial.
+const account = vi.hoisted(() => ({
+  user: { unitPreference: "metric", glucoseUnit: null } as Record<
+    string,
+    unknown
+  >,
+}));
+vi.mock("@/hooks/use-auth", () => ({
+  useAuth: () => ({ user: account.user, isAuthenticated: true }),
+  useAccountOnceMounted: () => account.user,
+}));
+
 /**
  * v1.4.32 — `<WorkoutList>` unit tests.
  *
@@ -47,6 +60,18 @@ describe("<WorkoutList>", () => {
     expect(html).toContain("320 kcal");
   });
 
+  it("states the distance in miles for an imperial reader", () => {
+    account.user = { unitPreference: "imperial", glucoseUnit: null };
+    try {
+      const html = render(<WorkoutList workouts={[ROW]} />);
+      // 5200 m = 3.23 mi.
+      expect(html).toContain("3.23 mi");
+      expect(html).not.toContain(" km");
+    } finally {
+      account.user = { unitPreference: "metric", glucoseUnit: null };
+    }
+  });
+
   it("renders aggregate average HR without claiming an HR series", () => {
     const html = render(
       <WorkoutList workouts={[{ ...ROW, hasHrSeries: false }]} />,

src/components/insights/metric-target-summary.tsx

@@ -8,7 +8,6 @@ import { useAuth } from "@/hooks/use-auth";
 import { useUnitDisplay } from "@/hooks/use-unit-display";
 import { queryKeys } from "@/lib/query-keys";
 import { useTranslations } from "@/lib/i18n/context";
-import { convertGlucose, resolveGlucoseUnit } from "@/lib/glucose";
 import { resolveTargetUnitAdapter } from "@/lib/targets/target-unit-display";
 import { Card, CardContent, CardHeader } from "@/components/ui/card";
 import { RangeBar } from "@/components/targets/range-bar";
@@ -18,6 +17,7 @@ import { TileHeader } from "@/components/insights/tile-header";
 import { useTargetAdjust } from "@/lib/insights/target-adjust-context";
 import { getTargetSourceLink } from "@/lib/targets/source-link";
 import { apiGet } from "@/lib/api/api-fetch";
+import { resolveGlucoseUnit, type GlucoseUnit } from "@/lib/glucose";
 
 /**
  * v1.8.0 → v1.8.5 — surface the per-metric target reference panel on each
@@ -152,28 +152,17 @@ export function MetricTargetSummary({ slug }: MetricTargetSummaryProps) {
   // mg/dL values to the user's display unit. The route's per-context
   // labels are i18n keys, so resolve them.
   if (isGlucose) {
-    const displayUnit = resolveGlucoseUnit(data.profile?.glucoseUnit ?? null);
-    const convert = (v: number | null) =>
-      v == null ? null : convertGlucose(v, displayUnit);
+    // The payload stays canonical mg/dL here; each panel converts through
+    // the shared target adapter, which owns the glucose unit as it owns
+    // pounds, so the panel and its edit sheet cannot convert twice.
+    const glucoseUnit = resolveGlucoseUnit(data.profile?.glucoseUnit ?? null);
     const panels = GLUCOSE_TARGET_TYPES.map((type) =>
       data.targets.find((entry) => entry.type === type),
     )
       .filter(
         (entry): entry is TargetItem => entry != null && entry.range != null,
       )
-      .map((entry) => ({
-        ...entry,
-        label: t(entry.label),
-        unit: displayUnit,
-        current: convert(entry.current),
-        average30: convert(entry.average30),
-        range: entry.range
-          ? {
-              min: convertGlucose(entry.range.min, displayUnit),
-              max: convertGlucose(entry.range.max, displayUnit),
-            }
-          : null,
-      }));
+      .map((entry) => ({ ...entry, label: t(entry.label) }));
 
     if (panels.length === 0) return null;
 
@@ -188,6 +177,7 @@ export function MetricTargetSummary({ slug }: MetricTargetSummaryProps) {
             key={panel.type}
             target={panel}
             heading={panel.label}
+            glucoseUnit={glucoseUnit}
           />
         ))}
       </div>
@@ -212,6 +202,12 @@ interface TargetReferencePanelProps {
   bpDiastolic?: TargetsResponse["bpDiastolic"];
   /** Optional sub-heading shown above the panel (used for glucose contexts). */
   heading?: string;
+  /**
+   * The record's glucose unit as the targets payload resolved it. The
+   * glucose panels pass it so the band reads in the unit the server
+   * resolved for this record; every other panel leaves it to the hook.
+   */
+  glucoseUnit?: GlucoseUnit;
 }
 
 /**
@@ -232,21 +228,26 @@ function TargetReferencePanel({
   target,
   bpDiastolic,
   heading,
+  glucoseUnit: payloadGlucoseUnit,
 }: TargetReferencePanelProps) {
   const { t } = useTranslations();
   const adjust = useTargetAdjust();
-  const { preference } = useUnitDisplay();
+  const { preference, glucoseUnit: accountGlucoseUnit } = useUnitDisplay();
+  const glucoseUnit = payloadGlucoseUnit ?? accountGlucoseUnit;
 
   // v1.32.27 — the panel renders in the user's preferred unit. The
   // `/api/insights/targets` payload is canonical (kg for weight); the
   // adapter converts it once, here, and everything downstream — the
   // range bar, the status pill, the 30-day average, and the edit
-  // sheet's seed — consumes the converted pair. Glucose contexts are
-  // pre-converted by the caller above and carry no display transform,
-  // so they take the adapter's identity path and are never scaled
-  // twice. For a metric account the adapter is the exact identity, so
-  // this panel is byte-identical to the previous release.
-  const units = resolveTargetUnitAdapter(target.type, target.unit, preference);
+  // sheet's seed — consumes the converted pair. The glucose contexts
+  // arrive canonical too and convert here to the reader's glucose unit.
+  // On the default preferences the adapter is the exact identity.
+  const units = resolveTargetUnitAdapter(
+    target.type,
+    target.unit,
+    preference,
+    glucoseUnit,
+  );
   const unit = units.unit;
   const range = target.range
     ? {

src/components/insights/trend-annotation.tsx

@@ -20,6 +20,7 @@ import {
 import { cn } from "@/lib/utils";
 import { CONFIDENCE_BADGE_CLASS } from "./confidence-badge";
 import { apiGet } from "@/lib/api/api-fetch";
+import { useUnitDisplay } from "@/hooks/use-unit-display";
 
 /**
  * v1.4.20 phase B3 — single-sentence AI annotation rendered directly
@@ -264,6 +265,7 @@ export function TrendDescriptorCaption({
 }) {
   const { t } = useTranslations();
   const { isAuthenticated } = useAuth();
+  const { toDisplay, toDisplayDelta, unitFor } = useUnitDisplay();
 
   const isMood = kind === "mood";
   const primaryType = types[0] ?? "";
@@ -323,18 +325,30 @@ export function TrendDescriptorCaption({
     }
     // The numeric series is already server-bounded to the trailing
     // 30-day window by the fetch, so every returned row is in-window.
+    // Described in the reader's unit, the same one the chart above plots.
     return (numericQuery.data ?? []).map((row) => ({
       timestamp: new Date(row.measuredAt).getTime(),
-      value: row.value,
+      value: toDisplay(primaryType, row.value),
     }));
-  }, [isMood, moodQuery.data, numericQuery.data]);
+  }, [isMood, moodQuery.data, numericQuery.data, toDisplay, primaryType]);
 
   const descriptor = useMemo(() => {
+    const meta = TREND_SLOT_DESCRIPTOR_META[metric];
+    // A slot that converts its series converts its noise floor with it: the
+    // floor is declared canonically and is a difference (factor only).
     const config = isMood
       ? MOOD_DESCRIPTOR_CONFIG
-      : TREND_SLOT_DESCRIPTOR_META[metric]?.config;
+      : meta?.unitType
+        ? {
+            ...meta.config,
+            absoluteFloor: toDisplayDelta(
+              meta.unitType,
+              meta.config.absoluteFloor,
+            ),
+          }
+        : meta?.config;
     return computeTrendDescriptor(points, config);
-  }, [points, isMood, metric]);
+  }, [points, isMood, metric, toDisplayDelta]);
 
   // Tier 4 — genuinely too few points (also covers the in-flight window
   // before the small series lands). Surface the real empty hint so the
@@ -361,7 +375,7 @@ export function TrendDescriptorCaption({
   // copy defensively (should not happen for the legacy triple).
   const copy = isMood
     ? moodDescriptorCopy(descriptor)
-    : (numericDescriptorCopy(metric, descriptor) ??
+    : (numericDescriptorCopy(metric, descriptor, unitFor) ??
       moodDescriptorCopy(descriptor));
 
   return (

src/components/insights/trends-row.tsx

@@ -22,6 +22,7 @@ import {
   type TrendAnnotationConfidenceBand,
   type TrendAnnotationStatus,
 } from "./trend-annotation";
+import { useUnitDisplay } from "@/hooks/use-unit-display";
 
 /**
  * Trends row — a small chart per metric above a one-sentence
@@ -116,17 +117,29 @@ function MetricChart({
   title: string;
 }) {
   const { user } = useAuth();
+  const { transformFor, isTransformed } = useUnitDisplay();
   const userTimezone = user?.timezone;
   if (config.kind === "mood") {
     return <MoodChart title={title} mini />;
   }
+  // A single transformed series (weight, distance, temperature) plots in
+  // the reader's unit: the chart folds scale and offset in at its read
+  // boundary, exactly as the metric's own insights page does. Distance
+  // used to plot raw metres under a "km" label for every reader.
+  const primary = config.types[0] ?? "";
+  const transform =
+    config.types.length === 1 && isTransformed(primary)
+      ? transformFor(primary)
+      : null;
   return (
     <HealthChartDynamicMini
       types={config.types}
       title={title}
       colors={config.colors}
-      unit={config.unit}
-      yAxisUnit={config.yAxisUnit}
+      unit={transform ? transform.displayUnit : config.unit}
+      yAxisUnit={transform ? undefined : config.yAxisUnit}
+      valueScale={transform?.factor}
+      valueOffset={transform?.offset}
       mini
       userTimezone={userTimezone}
     />

src/components/insights/workout-detail/format.ts

@@ -1,4 +1,10 @@
 import { getNumberFormat, getDateTimeFormat } from "@/lib/intl/formatter-cache";
+import {
+  applyDisplayTransform,
+  getQuantityTransform,
+  paceSecondsPerDistanceUnit,
+  type UnitPreference,
+} from "@/lib/measurements/display-transform";
 import {
   hourCycleOptions,
   type TimeFormatPreference,
@@ -27,12 +33,38 @@ export function formatDurationMinutes(seconds: number, locale: string): string {
   return formatNumber(minutes, locale);
 }
 
-export function formatDistanceKm(meters: number, locale: string): string {
-  const km = meters / 1000;
-  return getNumberFormat(locale, {
+/**
+ * A workout distance in the reader's unit, with its symbol: "5.80 km" or
+ * "3.60 mi". The workout list, the detail header, the stat tile and the
+ * sport-average line all print through this, so none of them can keep
+ * kilometres for an imperial reader.
+ */
+export function formatDistance(
+  meters: number,
+  locale: string,
+  preference: UnitPreference,
+): string {
+  const transform = getQuantityTransform("distance", preference);
+  const value = applyDisplayTransform(meters, transform);
+  const formatted = getNumberFormat(locale, {
     maximumFractionDigits: 2,
-    minimumFractionDigits: km < 10 ? 2 : 1,
-  }).format(km);
+    minimumFractionDigits: value < 10 ? 2 : 1,
+  }).format(value);
+  return `${formatted} ${transform.displayUnit}`;
+}
+
+/** Elevation gain in the reader's unit with its symbol: "123.4 m" / "404.9 ft". */
+export function formatElevation(
+  meters: number,
+  locale: string,
+  preference: UnitPreference,
+): string {
+  const transform = getQuantityTransform("elevation", preference);
+  return `${formatNumber(
+    applyDisplayTransform(meters, transform),
+    locale,
+    transform.decimals,
+  )} ${transform.displayUnit}`;
 }
 
 export function formatNumber(
@@ -46,21 +78,36 @@ export function formatNumber(
   }).format(value);
 }
 
-export function formatPaceMinPerKm(
+/**
+ * Average pace per kilometre or per mile, by the reader's preference. Only
+ * meaningful for run / walk / hike / ride; the caller gates on distance +
+ * sport.
+ */
+export function formatPace(
   durationSec: number,
   meters: number,
+  preference: UnitPreference,
 ): string {
-  // Seconds-per-kilometre. Only meaningful for run / walk / hike / ride;
-  // the caller gates on distance + sport.
-  const secPerKm = (durationSec / meters) * 1000;
-  return formatPaceSeconds(secPerKm);
+  return formatPaceSeconds(
+    paceSecondsPerDistanceUnit(durationSec, meters, preference),
+    getQuantityTransform("distance", preference).displayUnit,
+  );
 }
 
-/** "m:ss /km" from a seconds-per-km value (used by pace + splits). */
-export function formatPaceSeconds(secPerKm: number): string {
-  const m = Math.floor(secPerKm / 60);
-  const s = Math.round(secPerKm % 60);
-  return `${m}:${s.toString().padStart(2, "0")} /km`;
+/**
+ * "m:ss /km" from a seconds-per-unit value. The splits table passes "km"
+ * explicitly: its rows are kilometre segments cut server-side, so their
+ * pace is per kilometre whatever the preference.
+ */
+export function formatPaceSeconds(secPerUnit: number, unit: string): string {
+  let m = Math.floor(secPerUnit / 60);
+  let s = Math.round(secPerUnit % 60);
+  // 359.6 s is 6:00, not 5:60.
+  if (s === 60) {
+    m += 1;
+    s = 0;
+  }
+  return `${m}:${s.toString().padStart(2, "0")} /${unit}`;
 }
 
 export function formatDateRange(

src/components/insights/workout-detail/header.tsx

@@ -3,8 +3,9 @@
 import { useTranslations, useTimeFormatPreference } from "@/lib/i18n/context";
 import { iconForSport } from "@/lib/workouts/sport-icons";
 import type { WorkoutDetailPayload } from "@/hooks/use-workouts";
+import { useUnitDisplay } from "@/hooks/use-unit-display";
 
-import { formatDuration, formatDistanceKm, formatDateRange } from "./format";
+import { formatDuration, formatDistance, formatDateRange } from "./format";
 
 /**
  * Hero header — the at-a-glance verdict row. Sport icon badge, source
@@ -30,6 +31,7 @@ function renderSportIconBadge(sportType: string) {
 export function WorkoutDetailHeader({ workout }: WorkoutDetailHeaderProps) {
   const { t, locale } = useTranslations();
   const timeFormat = useTimeFormatPreference();
+  const { preference } = useUnitDisplay();
   const sportLabelKey = `insights.workouts.sport.${workout.sportType}`;
   const sportLabel = t(sportLabelKey);
   const sportName =
@@ -67,7 +69,7 @@ export function WorkoutDetailHeader({ workout }: WorkoutDetailHeaderProps) {
         </span>
         {workout.distanceM != null ? (
           <span className="text-muted-foreground text-xs tabular-nums">
-            {formatDistanceKm(workout.distanceM, locale)} km
+            {formatDistance(workout.distanceM, locale, preference)}
           </span>
         ) : null}
       </div>

src/components/insights/workout-detail/splits.tsx

@@ -70,7 +70,7 @@ export function WorkoutDetailSplits({ workout }: WorkoutDetailSplitsProps) {
                       : "py-1.5 text-right tabular-nums"
                   }
                 >
-                  {formatPaceSeconds(s.paceSecPerKm)}
+                  {formatPaceSeconds(s.paceSecPerKm, "km")}
                 </td>
               </tr>
             ))}

src/components/insights/workout-detail/stats.tsx

@@ -17,12 +17,15 @@ import { TileHeader } from "@/components/insights/tile-header";
 import { cn } from "@/lib/utils";
 import { useTranslations } from "@/lib/i18n/context";
 import type { WorkoutDetailPayload } from "@/hooks/use-workouts";
+import { useUnitDisplay } from "@/hooks/use-unit-display";
+import type { UnitPreference } from "@/lib/measurements/display-transform";
 
 import {
   formatDuration,
-  formatDistanceKm,
+  formatDistance,
+  formatElevation,
   formatNumber,
-  formatPaceMinPerKm,
+  formatPace,
   formatDurationMinutes,
 } from "./format";
 
@@ -69,12 +72,13 @@ const PACE_SPORTS = new Set(["walking", "running", "hiking", "cycling"]);
 function sportAverageLine(
   workout: WorkoutDetailPayload,
   locale: string,
+  preference: UnitPreference,
 ): string | null {
   const ctx = workout.sportContext;
   if (!ctx || ctx.count < 2) return null;
   const parts: string[] = [];
   if (ctx.avgDistanceM != null && ctx.avgDistanceM > 0) {
-    parts.push(`${formatDistanceKm(ctx.avgDistanceM, locale)} km`);
+    parts.push(formatDistance(ctx.avgDistanceM, locale, preference));
   }
   parts.push(`${formatDurationMinutes(ctx.avgDurationSec, locale)} min`);
   if (ctx.avgAvgHr != null) parts.push(`${ctx.avgAvgHr} bpm`);
@@ -83,6 +87,7 @@ function sportAverageLine(
 
 export function WorkoutDetailStats({ workout }: WorkoutDetailStatsProps) {
   const { t, locale } = useTranslations();
+  const { preference } = useUnitDisplay();
   const tiles: StatTileProps[] = [];
 
   tiles.push({
@@ -95,7 +100,7 @@ export function WorkoutDetailStats({ workout }: WorkoutDetailStatsProps) {
     tiles.push({
       icon: <Map className="size-4" />,
       label: t("insights.workouts.detail.statsDistance"),
-      value: `${formatDistanceKm(workout.distanceM, locale)} km`,
+      value: formatDistance(workout.distanceM, locale, preference),
     });
   }
 
@@ -139,7 +144,7 @@ export function WorkoutDetailStats({ workout }: WorkoutDetailStatsProps) {
     tiles.push({
       icon: <Mountain className="size-4" />,
       label: t("insights.workouts.detail.statsElevation"),
-      value: `${formatNumber(workout.elevationM, locale, 1)} m`,
+      value: formatElevation(workout.elevationM, locale, preference),
     });
   }
 
@@ -151,11 +156,11 @@ export function WorkoutDetailStats({ workout }: WorkoutDetailStatsProps) {
     tiles.push({
       icon: <Timer className="size-4" />,
       label: t("insights.workouts.detail.statsPace"),
-      value: formatPaceMinPerKm(workout.durationSec, workout.distanceM),
+      value: formatPace(workout.durationSec, workout.distanceM, preference),
     });
   }
 
-  const averageLine = sportAverageLine(workout, locale);
+  const averageLine = sportAverageLine(workout, locale, preference);
 
   return (
     <Card data-slot="workout-detail-stats">

src/components/insights/workout-list.tsx

@@ -13,6 +13,8 @@ import {
 import { iconForSport } from "@/lib/workouts/sport-icons";
 import type { WorkoutListEntry } from "@/hooks/use-workouts";
 import { Button } from "@/components/ui/button";
+import { useUnitDisplay } from "@/hooks/use-unit-display";
+import { formatDistance } from "@/components/insights/workout-detail/format";
 
 /**
  * v1.4.32 — workout list row primitive.
@@ -33,14 +35,6 @@ function formatDuration(seconds: number): string {
   return `${m}m`;
 }
 
-function formatDistanceKm(meters: number, locale: string): string {
-  const km = meters / 1000;
-  return getNumberFormat(locale, {
-    maximumFractionDigits: 2,
-    minimumFractionDigits: km < 10 ? 2 : 1,
-  }).format(km);
-}
-
 function formatEnergy(kcal: number, locale: string): string {
   return getNumberFormat(locale, {
     maximumFractionDigits: 0,
@@ -86,6 +80,7 @@ export function WorkoutList({
 }: WorkoutListProps) {
   const { t, locale } = useTranslations();
   const timeFormat = useTimeFormatPreference();
+  const { preference } = useUnitDisplay();
 
   return (
     <ul
@@ -150,7 +145,7 @@ export function WorkoutList({
                 <span className="text-muted-foreground flex flex-wrap justify-end gap-x-2 tabular-nums">
                   {workout.distanceM != null ? (
                     <span data-slot="workout-list-distance">
-                      {formatDistanceKm(workout.distanceM, locale)} km
+                      {formatDistance(workout.distanceM, locale, preference)}
                     </span>
                   ) : null}
                   {workout.activeEnergyKcal != null ? (

src/components/settings/__tests__/thresholds-editor-glucose-unit.test.tsx

@@ -0,0 +1,76 @@
+/**
+ * The settings threshold editor reads glucose in the reader's unit.
+ *
+ * It used to pass every glucose threshold through the identity path, so an
+ * mmol/L account was shown "Default: 70–99 mg/dL" and mg/dL input fields
+ * bounded at 40–400, while the insights sheet for the same threshold already
+ * spoke mmol/L. The stored value stays canonical mg/dL either way.
+ */
+import { describe, expect, it, vi } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+const authUser = vi.hoisted(() => ({
+  current: { glucoseUnit: "mmol/L", unitPreference: "metric" } as Record<
+    string,
+    unknown
+  >,
+}));
+
+vi.mock("@/hooks/use-auth", () => ({
+  useAuth: () => ({ user: authUser.current, isAuthenticated: true }),
+  useAccountOnceMounted: () => authUser.current,
+}));
+
+vi.mock("@tanstack/react-query", () => ({
+  useQuery: () => ({
+    isLoading: false,
+    data: {
+      effective: {
+        BLOOD_GLUCOSE_FASTING: {
+          range: { greenMin: 72, greenMax: 108 },
+          isOverride: true,
+          default: { greenMin: 70, greenMax: 99 },
+          bounds: { min: 40, max: 400, unit: "mg/dL" },
+        },
+      },
+      overrides: { BLOOD_GLUCOSE_FASTING: { min: 72, max: 108 } },
+    },
+  }),
+  useMutation: () => ({ mutate: vi.fn(), isPending: false }),
+  useQueryClient: () => ({ invalidateQueries: vi.fn() }),
+}));
+
+import { I18nProvider } from "@/lib/i18n/context";
+import { ThresholdsEditorSection } from "../thresholds-editor-section";
+
+function render(): string {
+  return renderToStaticMarkup(
+    <I18nProvider initialLocale="en">
+      <ThresholdsEditorSection id="thresholds" />
+    </I18nProvider>,
+  );
+}
+
+describe("<ThresholdsEditorSection> glucose unit", () => {
+  it("states the default, the fields and the bounds in mmol/L", () => {
+    authUser.current = { glucoseUnit: "mmol/L", unitPreference: "metric" };
+    const html = render();
+    // 70–99 mg/dL is 3.9–5.5 mmol/L.
+    expect(html).toMatch(/3\.9–5\.5 mmol\/L/);
+    expect(html).not.toMatch(/70(\.0)?–99(\.0)? mg\/dL/);
+    // The stored 72–108 mg/dL override seeds 4–6 mmol/L.
+    expect(html).toContain('value="4"');
+    expect(html).toContain('value="6"');
+    // Inward-rounded guardrail of 40–400 mg/dL.
+    expect(html).toContain('min="2.3"');
+    expect(html).toContain('max="22.1"');
+  });
+
+  it("keeps mg/dL for an mg/dL reader", () => {
+    authUser.current = { glucoseUnit: "mg/dL", unitPreference: "metric" };
+    const html = render();
+    expect(html).toMatch(/70(\.0)?–99(\.0)? mg\/dL/);
+    expect(html).toContain('value="72"');
+    expect(html).toContain('min="40"');
+  });
+});

src/components/settings/thresholds-editor-section.tsx

@@ -237,7 +237,7 @@ function MetricRow({
 }: MetricRowProps) {
   const { t } = useTranslations();
   const fmt = useFormatters();
-  const { preference } = useUnitDisplay();
+  const { preference, glucoseUnit } = useUnitDisplay();
   const canonicalBounds = METRIC_BOUNDS[metric];
 
   // v1.32.27 — the row reads and writes in the user's preferred unit
@@ -246,12 +246,14 @@ function MetricRow({
   // canonical, so it converts on the way into the fields and inverts on
   // the way back out in `onSave`. Guardrails round inward so a value
   // typed at the displayed limit still passes the server's canonical
-  // check. Metrics without a transform — and every metric for a metric
-  // user — take the adapter's identity path untouched.
+  // check. The glucose thresholds read in the reader's glucose unit the
+  // same way. Metrics without a transform — and every metric on the default
+  // preferences — take the adapter's identity path untouched.
   const units = resolveTargetUnitAdapter(
     metric,
     canonicalBounds.unit,
     preference,
+    glucoseUnit,
   );
   const bounds = { ...units.bounds(canonicalBounds), unit: units.unit };
 

src/components/targets/target-edit-sheet.tsx

@@ -17,8 +17,11 @@ import {
   type ThresholdMetric,
   type EffectiveRange,
 } from "@/lib/analytics/effective-range";
-import { convertGlucose, toCanonicalMgdl } from "@/lib/glucose";
-import { resolveTargetUnitAdapter } from "@/lib/targets/target-unit-display";
+import {
+  isGlucoseTargetMetric,
+  resolveTargetUnitAdapter,
+} from "@/lib/targets/target-unit-display";
+import { resolveGlucoseUnit } from "@/lib/glucose";
 import { useUnitDisplay } from "@/hooks/use-unit-display";
 import { apiDelete, apiGet, apiPut } from "@/lib/api/api-fetch";
 
@@ -129,49 +132,33 @@ function TargetEditSheetBody({
   const metric = TARGET_TYPE_TO_METRIC[targetType] ?? null;
   const isDerivedMetric = !isBp && metric == null;
 
-  // Glucose is the one metric whose display unit can differ from the
-  // canonical storage unit: HealthLog stores mg/dL, but a user on the
-  // mmol/L preference sees — and types — mmol/L. The parent already
-  // hands us `unit="mmol/L"` and a `initialRange` pre-converted to that
-  // unit. We must therefore (a) seed the mg/dL persisted override into
-  // the display unit, (b) validate the typed value against bounds
-  // expressed in the display unit, and (c) convert the typed value back
-  // to canonical mg/dL before the PUT — otherwise a `5.5 mmol/L` target
-  // is rejected by the 40–400 mg/dL bounds or stored verbatim as 5.5.
-  const isGlucoseMmol =
-    metric != null && metric.startsWith("BLOOD_GLUCOSE") && unit === "mmol/L";
-
-  // v1.32.27 — the same coupled treatment now covers the metric/imperial
-  // preference. Weight-class thresholds are stored in kg; an imperial
-  // user seeds, validates, and types in lb, and the adapter inverts the
-  // typed number back to kg before the PUT. Glucose keeps its own
-  // mg/dL ↔ mmol/L dialect (it carries no display transform, so the two
-  // never compose); every other metric takes the adapter's identity
-  // path and is numerically untouched.
-  const { preference } = useUnitDisplay();
+  // One adapter owns every direction of the unit conversion: an imperial
+  // user seeds, validates and types weight-class thresholds in pounds, an
+  // mmol/L user types glucose thresholds in mmol/L, and the typed number is
+  // inverted back to the canonical kg / mg/dL before the PUT. The parent
+  // hands `unit` and `initialRange` already in the display unit; the
+  // persisted override and `METRIC_BOUNDS` are canonical and go through the
+  // adapter. Every other metric takes the identity path.
+  // A glucose sheet speaks the unit its panel registered, so the sheet and
+  // the band it edits can never disagree.
+  const { preference, glucoseUnit: accountGlucoseUnit } = useUnitDisplay();
+  const adapterKey = isBp ? "BLOOD_PRESSURE_SYS" : (metric ?? "");
   const units = resolveTargetUnitAdapter(
-    isBp ? "BLOOD_PRESSURE_SYS" : (metric ?? ""),
+    adapterKey,
     unit,
     preference,
+    isGlucoseTargetMetric(adapterKey)
+      ? resolveGlucoseUnit(unit)
+      : accountGlucoseUnit,
   );
 
-  const toDisplay = (canonical: number) =>
-    isGlucoseMmol
-      ? convertGlucose(canonical, "mmol/L")
-      : units.toDisplay(canonical);
-  const toCanonical = (displayValue: number) =>
-    isGlucoseMmol
-      ? toCanonicalMgdl(displayValue, "mmol/L")
-      : units.toCanonical(displayValue);
-  // Guardrails the typed value is checked against, expressed in the
-  // display unit. Glucose projects its mg/dL window through the same
-  // conversion the fields use; every other metric rounds the window
-  // INWARD so a value typed at the display bound never inverts to a
-  // canonical value the server rejects.
+  const toDisplay = (canonical: number) => units.toDisplay(canonical);
+  const toCanonical = (displayValue: number) => units.toCanonical(displayValue);
+  // Guardrails the typed value is checked against, expressed in the display
+  // unit and rounded INWARD so a value typed at the display bound never
+  // inverts to a canonical value the server rejects.
   const toDisplayBounds = (canonical: { min: number; max: number }) =>
-    isGlucoseMmol
-      ? { min: toDisplay(canonical.min), max: toDisplay(canonical.max) }
-      : units.bounds(canonical);
+    units.bounds(canonical);
 
   // Lazy-load the thresholds payload so the dialog also catches any
   // already-persisted override even when the seeded `initialRange`