diff --git a/packages/ui/src/features/autoresearch/AutoresearchObservability.test.tsx b/packages/ui/src/features/autoresearch/AutoresearchObservability.test.tsx
new file mode 100644
index 0000000000..959ed74ad3
--- /dev/null
+++ b/packages/ui/src/features/autoresearch/AutoresearchObservability.test.tsx
@@ -0,0 +1,95 @@
+import type { AutoresearchRun } from "@posthog/core/autoresearch/schemas";
+import type { AcpMessage } from "@posthog/shared";
+import { Theme } from "@radix-ui/themes";
+import { render, screen } from "@testing-library/react";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { AutoresearchObservability } from "./AutoresearchObservability";
+
+const STARTED_AT = 1_000;
+
+function makeRun(overrides: Partial<AutoresearchRun> = {}): AutoresearchRun {
+  return {
+    id: "run-1",
+    config: {
+      taskId: "task-1",
+      direction: "minimize",
+      targetValue: null,
+      maxIterations: 10,
+      implementModel: null,
+      measureModel: null,
+      implementEffort: null,
+      measureEffort: null,
+      instructions: "Reduce memory usage.",
+    },
+    status: "running",
+    metricName: null,
+    metricUnit: null,
+    phase: null,
+    originalModel: null,
+    originalEffort: null,
+    researchFindings: [],
+    iterations: [],
+    startedAt: STARTED_AT,
+    endedAt: null,
+    endReason: null,
+    interruptedReason: null,
+    lastError: null,
+    ...overrides,
+  };
+}
+
+function toolCall(ts: number, kind: string): AcpMessage {
+  return {
+    type: "acp_message",
+    ts,
+    message: {
+      jsonrpc: "2.0",
+      method: "session/update",
+      params: {
+        update: {
+          sessionUpdate: "tool_call",
+          title: `tool at ${ts}`,
+          kind,
+          status: "completed",
+        },
+      },
+    },
+  } as AcpMessage;
+}
+
+function renderObservability(run: AutoresearchRun, events: AcpMessage[]) {
+  return render(
+    <Theme>
+      <AutoresearchObservability run={run} events={events} />
+    </Theme>,
+  );
+}
+
+describe("AutoresearchObservability", () => {
+  afterEach(() => vi.useRealTimers());
+
+  it("keeps observed-time bars within range when a kind outlasts wall-clock", () => {
+    // Live run where the latest tool timestamp sits ahead of `now` (clock skew
+    // between agent-set event timestamps and the client clock). The activity
+    // analysis then attributes more elapsed time to one kind than the run's
+    // wall-clock duration, which used to push Progress past its max of 100.
+    vi.useFakeTimers();
+    vi.setSystemTime(STARTED_AT + 10_000);
+
+    renderObservability(makeRun(), [
+      toolCall(STARTED_AT, "edit"),
+      toolCall(STARTED_AT + 25_000, "execute"),
+    ]);
+
+    const bars = screen.getAllByRole("progressbar");
+    expect(bars).toHaveLength(4);
+    for (const bar of bars) {
+      const now = bar.getAttribute("aria-valuenow");
+      // A rejected (out-of-range) value renders no aria-valuenow at all.
+      expect(now).not.toBeNull();
+      const value = Number(now);
+      expect(value).toBeGreaterThanOrEqual(0);
+      expect(value).toBeLessThanOrEqual(100);
+    }
+  });
+});
diff --git a/packages/ui/src/features/autoresearch/AutoresearchObservability.tsx b/packages/ui/src/features/autoresearch/AutoresearchObservability.tsx
index f047768fff..a4f3bdf0ab 100644
--- a/packages/ui/src/features/autoresearch/AutoresearchObservability.tsx
+++ b/packages/ui/src/features/autoresearch/AutoresearchObservability.tsx
@@ -150,7 +150,12 @@ function TimeRow({
   value: number;
   total: number;
 }) {
-  const percentage = Math.round((value / total) * 100);
+  // Per-kind observed time can exceed the run's wall-clock duration, so clamp
+  // before handing the value to Progress (whose max defaults to 100).
+  const percentage =
+    total > 0
+      ? Math.min(100, Math.max(0, Math.round((value / total) * 100)))
+      : 0;
   return (
     <div>
       <div className="mb-1 flex items-center justify-between gap-3">
diff --git a/packages/ui/src/features/billing/UsageButton.tsx b/packages/ui/src/features/billing/UsageButton.tsx
index 95b42d3001..01533babc9 100644
--- a/packages/ui/src/features/billing/UsageButton.tsx
+++ b/packages/ui/src/features/billing/UsageButton.tsx
@@ -59,7 +59,10 @@ export function UsageButton() {
     usage.sustained.used_percent >= usage.burst.used_percent
       ? usage.sustained
       : usage.burst;
-  const usagePercent = Math.min(Math.round(dominant.used_percent), 100);
+  const usagePercent = Math.min(
+    Math.max(Math.round(dominant.used_percent), 0),
+    100,
+  );
   const resetLabel = formatResetTime(dominant.reset_at);
 
   const handleOpenChange = (nextOpen: boolean) => {
diff --git a/packages/ui/src/features/billing/UsageMeter.tsx b/packages/ui/src/features/billing/UsageMeter.tsx
index 65bb71ddd9..7f9281dd10 100644
--- a/packages/ui/src/features/billing/UsageMeter.tsx
+++ b/packages/ui/src/features/billing/UsageMeter.tsx
@@ -10,6 +10,9 @@ interface UsageMeterProps {
 
 export function UsageMeter({ label, bucket, color }: UsageMeterProps) {
   const percentage = bucket.used_percent;
+  // used_percent can exceed 100 once a limit is blown; the text still shows the
+  // true figure, but Progress rejects values above its default max of 100.
+  const progressValue = Math.min(100, Math.max(0, percentage));
 
   const borderColor = color === "red" ? "var(--red-7)" : "var(--gray-5)";
 
@@ -28,7 +31,7 @@ export function UsageMeter({ label, bucket, color }: UsageMeterProps) {
         <Text className="font-medium text-sm">{percentage.toFixed(2)}%</Text>
       </Flex>
       <Progress
-        value={percentage}
+        value={progressValue}
         size="2"
         color={color === "red" ? "red" : undefined}
       />
diff --git a/packages/ui/src/features/updates/UpdateAvailableModal.tsx b/packages/ui/src/features/updates/UpdateAvailableModal.tsx
index 733959a868..e5c873cdc2 100644
--- a/packages/ui/src/features/updates/UpdateAvailableModal.tsx
+++ b/packages/ui/src/features/updates/UpdateAvailableModal.tsx
@@ -72,7 +72,7 @@ export function UpdateAvailableModal() {
     enabled: isOpen || prefetchForActiveUpdate,
   });
 
-  const percent = Math.round(downloadPercent ?? 0);
+  const percent = Math.min(100, Math.max(0, Math.round(downloadPercent ?? 0)));
   const sizeLabel = formatSize(downloadSizeBytes);
   const isDownloading = status === "downloading";
   const isReady = status === "ready" || status === "installing";