diff --git a/src/__tests__/display-transform-rounding-guard.test.ts b/src/__tests__/display-transform-rounding-guard.test.ts
index 7db775374..73b928296 100644
--- a/src/__tests__/display-transform-rounding-guard.test.ts
+++ b/src/__tests__/display-transform-rounding-guard.test.ts
@@ -52,7 +52,7 @@ const REGISTRY = "lib/measurements/display-transform.ts";
 const UNROUNDED_IMPORTERS = ["lib/targets/target-unit-display.ts"];
 
 /**
- * The surfaces allowed to read a transform's raw `factor` / `offset`. All four
+ * The surfaces allowed to read a transform's raw `factor` / `offset`. All five
  * do it for the same reason: the chart takes the multiplier as a prop, folds
  * it into its own series at the single read boundary, and formats the result
  * itself. Everything those files RENDER directly goes through the rounding
@@ -61,6 +61,9 @@ const UNROUNDED_IMPORTERS = ["lib/targets/target-unit-display.ts"];
  */
 const RAW_SCALE_SURFACES = [
   "app/page-client.tsx",
+  // The insights trends row: a single transformed series hands its scale
+  // and offset to the mini chart, which formats every value itself.
+  "components/insights/trends-row.tsx",
   "app/insights/weight/page.tsx",
   "components/insights/healthkit-metric-page.tsx",
   "components/insights/device-score-tile.tsx",
diff --git a/src/components/charts/workout-elevation-chart.tsx b/src/components/charts/workout-elevation-chart.tsx
index 3fd0cfa93..dbf0382fc 100644
--- a/src/components/charts/workout-elevation-chart.tsx
+++ b/src/components/charts/workout-elevation-chart.tsx
@@ -13,7 +13,7 @@ import {
 import { useTranslations } from "@/lib/i18n/context";
 import { useUnitDisplay } from "@/hooks/use-unit-display";
 import {
-  applyDisplayTransformUnrounded,
+  applyDisplayTransform,
   getQuantityTransform,
 } from "@/lib/measurements/display-transform";
 
@@ -41,8 +41,8 @@ export function WorkoutElevationChart({
   const distance = getQuantityTransform("distance", preference);
   const elevation = getQuantityTransform("elevation", preference);
   const data = points.map((p) => ({
-    dist: applyDisplayTransformUnrounded(p.distanceM, distance),
-    alt: applyDisplayTransformUnrounded(p.altitude, elevation),
+    dist: applyDisplayTransform(p.distanceM, distance),
+    alt: applyDisplayTransform(p.altitude, elevation),
   }));
 
   return (
diff --git a/src/components/insights/trend-annotation.tsx b/src/components/insights/trend-annotation.tsx
index 5b72e9ba9..7551a88cc 100644
--- a/src/components/insights/trend-annotation.tsx
+++ b/src/components/insights/trend-annotation.tsx
@@ -265,7 +265,7 @@ export function TrendDescriptorCaption({
 }) {
   const { t } = useTranslations();
   const { isAuthenticated } = useAuth();
-  const { toDisplay, transformFor, unitFor } = useUnitDisplay();
+  const { toDisplay, toDisplayDelta, unitFor } = useUnitDisplay();
 
   const isMood = kind === "mood";
   const primaryType = types[0] ?? "";
@@ -334,19 +334,21 @@ export function TrendDescriptorCaption({
 
   const descriptor = useMemo(() => {
     const meta = TREND_SLOT_DESCRIPTOR_META[metric];
-    // A slot that converts its series converts its noise floor with it (a
-    // floor is a difference: factor only).
+    // 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
       : meta?.unitType
         ? {
             ...meta.config,
-            absoluteFloor:
-              meta.config.absoluteFloor * transformFor(meta.unitType).factor,
+            absoluteFloor: toDisplayDelta(
+              meta.unitType,
+              meta.config.absoluteFloor,
+            ),
           }
         : meta?.config;
     return computeTrendDescriptor(points, config);
-  }, [points, isMood, metric, transformFor]);
+  }, [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
diff --git a/src/components/insights/workout-detail/format.ts b/src/components/insights/workout-detail/format.ts
index 03e559ea1..9dfb6eadd 100644
--- a/src/components/insights/workout-detail/format.ts
+++ b/src/components/insights/workout-detail/format.ts
@@ -1,7 +1,6 @@
 import { getNumberFormat, getDateTimeFormat } from "@/lib/intl/formatter-cache";
 import {
   applyDisplayTransform,
-  applyDisplayTransformUnrounded,
   getQuantityTransform,
   paceSecondsPerDistanceUnit,
   type UnitPreference,
@@ -46,7 +45,7 @@ export function formatDistance(
   preference: UnitPreference,
 ): string {
   const transform = getQuantityTransform("distance", preference);
-  const value = applyDisplayTransformUnrounded(meters, transform);
+  const value = applyDisplayTransform(meters, transform);
   const formatted = getNumberFormat(locale, {
     maximumFractionDigits: 2,
     minimumFractionDigits: value < 10 ? 2 : 1,
diff --git a/src/lib/insights/narrative/__tests__/period-narrative.test.ts b/src/lib/insights/narrative/__tests__/period-narrative.test.ts
index 99e3c7e68..83abb0ed5 100644
--- a/src/lib/insights/narrative/__tests__/period-narrative.test.ts
+++ b/src/lib/insights/narrative/__tests__/period-narrative.test.ts
@@ -156,15 +156,15 @@ describe("assemblePeriodNarrativeContext — the reader's units", () => {
     );
     const g = ctx.metricDeltas.find((d) => d.type === "BLOOD_GLUCOSE")!;
     expect(g.unit).toBe("mmol/L");
-    expect(g.current).toBe(5.99);
-    expect(g.prior).toBe(4.99);
+    expect(g.current).toBe(6);
+    expect(g.prior).toBe(5);
     expect(g.delta).toBe(1);
     // Percent is unit-free.
     expect(g.deltaPercent).toBe(20);
     const w = ctx.metricDeltas.find((d) => d.type === "WEIGHT")!;
     expect(w.unit).toBe("lb");
-    expect(w.current).toBe(180.78);
-    expect(w.delta).toBe(4.41);
+    expect(w.current).toBe(180.8);
+    expect(w.delta).toBe(4.4);
 
     const prose = buildDeterministicNarrative(ctx, "en");
     expect(prose).toContain("mmol/L");
@@ -172,7 +172,7 @@ describe("assemblePeriodNarrativeContext — the reader's units", () => {
     expect(prose).not.toContain("mg/dL");
     expect(prose).not.toContain("kg");
     const prompt = buildNarrativeUserPrompt(ctx, "en");
-    expect(prompt).toContain("BLOOD_GLUCOSE: 5.99 mmol/L");
+    expect(prompt).toContain("BLOOD_GLUCOSE: 6 mmol/L");
     expect(prompt).not.toContain("mg/dL");
   });
 
@@ -231,10 +231,10 @@ describe("assemblePeriodNarrativeContext — the reader's units", () => {
     );
     const t = ctx.bandTransitions.find((b) => b.type === "BLOOD_GLUCOSE")!;
     expect(t.unit).toBe("mmol/L");
-    expect(t.center).toBe(7.77);
+    expect(t.center).toBe(7.8);
     expect(t.movedOut).toBe(true);
     expect(buildNarrativeUserPrompt(ctx, "en")).toContain(
-      "BLOOD_GLUCOSE: 7.77 mmol/L",
+      "BLOOD_GLUCOSE: 7.8 mmol/L",
     );
   });
 });
diff --git a/src/lib/insights/narrative/period-narrative.ts b/src/lib/insights/narrative/period-narrative.ts
index c03deab01..807ade7f6 100644
--- a/src/lib/insights/narrative/period-narrative.ts
+++ b/src/lib/insights/narrative/period-narrative.ts
@@ -57,7 +57,8 @@ import { assembleDiscoveryMatrix } from "@/lib/insights/discovery-matrix";
 import { resolveModuleMap } from "@/lib/modules/gate";
 import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 import {
-  applyDisplayTransformUnrounded,
+  applyDisplayTransform,
+  applyDisplayTransformDelta,
   getReadingTransform,
   isUnitSensitiveType,
   resolveUnitPreferences,
@@ -135,8 +136,10 @@ function narratedUnit(
     const transform = getReadingTransform(type, units);
     return {
       unit: transform.displayUnit,
-      abs: (v) => round2(applyDisplayTransformUnrounded(v, transform)),
-      delta: (v) => round2(v * transform.factor),
+      // Rounded to the unit's own grain (one decimal for lb and mmol/L), the
+      // grain every screen shows the same reading at.
+      abs: (v) => round2(applyDisplayTransform(v, transform)),
+      delta: (v) => round2(applyDisplayTransformDelta(v, transform)),
     };
   }
   if (type === "SLEEP_DURATION") {
diff --git a/src/lib/insights/trend-descriptor.ts b/src/lib/insights/trend-descriptor.ts
index f42dd31aa..fea9ec7a7 100644
--- a/src/lib/insights/trend-descriptor.ts
+++ b/src/lib/insights/trend-descriptor.ts
@@ -148,7 +148,8 @@ export interface TrendSlotDescriptorMeta {
   /**
    * For a metric whose unit follows the reader's preference: the
    * measurement type the caller resolves the unit of (and converts the
-   * series and the noise floor through) before describing it.
+   * series and the noise floor through) before describing it. Such a slot
+   * declares its `absoluteFloor` in the CANONICAL unit (kg, m, °C).
    */
   unitType?: string;
   config: TrendDescriptorConfig;
@@ -196,7 +197,8 @@ export const TREND_SLOT_DESCRIPTOR_META: Record<
   },
   distance: {
     unitType: "WALKING_RUNNING_DISTANCE",
-    config: { absoluteFloor: 0.3, relativeFloor: 0.05, decimals: 1 },
+    // 300 m — canonical metres, converted to the reader's km or mi.
+    config: { absoluteFloor: 300, relativeFloor: 0.05, decimals: 1 },
   },
   vo2_max: {
     unit: "",