diff --git a/packages/tui/src/routes/session/index.tsx b/packages/tui/src/routes/session/index.tsx
index eb382baba95..3a405b778a4 100644
--- a/packages/tui/src/routes/session/index.tsx
+++ b/packages/tui/src/routes/session/index.tsx
@@ -89,6 +89,7 @@ import {
   createSessionRows,
   messageBoundaryIDs,
   resolvePart,
+  turnDuration,
   type CacheUsage,
   type PartRef,
   type SessionRow,
@@ -1601,6 +1602,7 @@ function SessionGroupView(props: {
 
 function AssistantFooter(props: { message: SessionMessageAssistant }) {
   const ctx = use()
+  const data = useData()
   const local = useLocal()
   const dimensions = useTerminalDimensions()
   const theme = useTheme("elevated")
@@ -1611,9 +1613,7 @@ function AssistantFooter(props: { message: SessionMessageAssistant }) {
         .find((model) => model.providerID === props.message.model.providerID && model.id === props.message.model.id)
         ?.name ?? `${props.message.model.providerID}/${props.message.model.id}`,
   )
-  const duration = createMemo(() =>
-    props.message.time.completed ? props.message.time.completed - props.message.time.created : 0,
-  )
+  const duration = createMemo(() => turnDuration(props.message, data.session.message.list(ctx.sessionID)))
   const interrupted = createMemo(() => props.message.error?.message === "Step interrupted")
   return (
     <>
diff --git a/packages/tui/src/routes/session/rows.ts b/packages/tui/src/routes/session/rows.ts
index 8540c23be17..73f4ef8d764 100644
--- a/packages/tui/src/routes/session/rows.ts
+++ b/packages/tui/src/routes/session/rows.ts
@@ -348,6 +348,15 @@ export function cacheReuseDrop(previous: CacheUsage | undefined, current: CacheU
   return drop > 0 ? drop : undefined
 }
 
+export function turnDuration(message: SessionMessageAssistant, messages: SessionMessageInfo[]) {
+  if (message.time.completed === undefined) return 0
+  const index = messages.findIndex((item) => item.id === message.id)
+  const input = messages
+    .slice(0, index === -1 ? messages.length : index)
+    .findLast((item) => item.type === "user" || item.type === "synthetic")
+  return Math.max(0, message.time.completed - (input?.time.created ?? message.time.created))
+}
+
 function hasTokenUsage(
   message: SessionMessageAssistant,
 ): message is SessionMessageAssistant & { tokens: NonNullable<SessionMessageAssistant["tokens"]> } {
diff --git a/packages/tui/test/cli/tui/session-rows.test.ts b/packages/tui/test/cli/tui/session-rows.test.ts
index 4e7f87152db..74fcf08e8ac 100644
--- a/packages/tui/test/cli/tui/session-rows.test.ts
+++ b/packages/tui/test/cli/tui/session-rows.test.ts
@@ -1,6 +1,20 @@
 import { expect, test } from "bun:test"
 import type { SessionMessageAssistant, SessionMessageInfo } from "@opencode-ai/client"
-import { cacheReuseDrop, messageBoundaryIDs, reduceSessionRows } from "../../../src/routes/session/rows"
+import { cacheReuseDrop, messageBoundaryIDs, reduceSessionRows, turnDuration } from "../../../src/routes/session/rows"
+
+test("measures turn duration from the user prompt across assistant steps", () => {
+  const first = assistant("assistant-1", [])
+  first.time = { created: 8_000, completed: 11_000 }
+  const final = assistant("assistant-2", [])
+  final.time = { created: 27_000, completed: 30_000 }
+  const messages: SessionMessageInfo[] = [
+    { type: "user", id: "user-1", text: "Question", time: { created: 1_000 } },
+    first,
+    final,
+  ]
+
+  expect(turnDuration(final, messages)).toBe(29_000)
+})
 
 test("filters OpenAI cache quantization from cache reuse drops", () => {
   const openai = { id: "gpt", providerID: "openai" }