diff --git a/packages/junior-dashboard/e2e/conversation-details.spec.ts b/packages/junior-dashboard/e2e/conversation-details.spec.ts
index 8259cb8122..a3d294c999 100644
--- a/packages/junior-dashboard/e2e/conversation-details.spec.ts
+++ b/packages/junior-dashboard/e2e/conversation-details.spec.ts
@@ -48,11 +48,11 @@ test("opens conversation details beside the chat", async ({
   });
   // Wide viewports open details beside the chat by default.
   await expect(details).toBeVisible();
-  // Run facts live in details only, not in the title bar.
+  // Cost stays in the title bar. Desktop details hide their copy of it.
   const costMetric = page
     .getByRole("main")
     .locator('span[tabindex="0"]')
-    .filter({ hasText: /^\$0\.03$/ });
+    .filter({ hasText: /^\$0\.03$/, visible: true });
   await expect(costMetric).toHaveCount(1);
   // Tooltips open on keyboard focus, not on focus after a mouse click. A key
   // press first makes this a keyboard focus.
@@ -72,7 +72,7 @@ test("opens conversation details beside the chat", async ({
   ).toHaveAttribute("href", "https://github.com/getsentry/payments/pull/77");
   await detailsButton.click();
   await expect(details).toBeHidden();
-  await expect(costMetric).toHaveCount(0);
+  await expect(costMetric).toHaveCount(1);
   await context.grantPermissions(["clipboard-read", "clipboard-write"], {
     origin: dashboard.baseURL,
   });
diff --git a/packages/junior-dashboard/src/client/conversations/ConversationHeader.tsx b/packages/junior-dashboard/src/client/conversations/ConversationHeader.tsx
index 22acf3c50a..a15b835c84 100644
--- a/packages/junior-dashboard/src/client/conversations/ConversationHeader.tsx
+++ b/packages/junior-dashboard/src/client/conversations/ConversationHeader.tsx
@@ -20,14 +20,17 @@ import { ShareConversationButton } from "./ShareConversationButton";
 import type { TranscriptViewMode } from "./transcriptRenderModel";
 
 /**
- * Show the conversation title bar: where it runs, the title, and actions.
- * Run facts, linked work, and the Brief live in Conversation details.
+ * Show the conversation title bar: where it runs, the title, its cost, and
+ * actions. Other run facts, linked work, and the Brief live in Conversation
+ * details.
  */
 export function ConversationHeader(props: {
   /** Parent chain of a child Conversation. Root Conversations omit it. */
   agentTree?: ReactNode;
   /** A `menu` layout copy action for the `⋯` menu. */
   copyAction?: ReactNode;
+  /** Estimated cost. Desktop only; mobile shows it in Conversation details. */
+  cost?: ReactNode;
   archive: ConversationArchiveAction;
   conversationId: string;
   detailsOpen: boolean;
@@ -179,6 +182,11 @@ export function ConversationHeader(props: {
             <span className="shrink-0">{props.privacy}</span>
           </div>
           <div className="flex shrink-0 items-center gap-0.5">
+            {props.cost ? (
+              <span className="mr-2 text-xs tabular-nums text-dashboard-text-muted">
+                {props.cost}
+              </span>
+            ) : null}
             {props.view === "raw" ? (
               // Event log is a debug view reached from the menu. Say which
               // view this is, and give one click back.
diff --git a/packages/junior-dashboard/src/client/conversations/ConversationMeta.tsx b/packages/junior-dashboard/src/client/conversations/ConversationMeta.tsx
index 5c10dc37ea..14f53a54f6 100644
--- a/packages/junior-dashboard/src/client/conversations/ConversationMeta.tsx
+++ b/packages/junior-dashboard/src/client/conversations/ConversationMeta.tsx
@@ -568,6 +568,37 @@ export function conversationLocation(
   );
 }
 
+/**
+ * Show the estimated cost of a conversation with its breakdown tooltip.
+ * Returns null until there is a cost or a live run to show.
+ */
+export function conversationCost(
+  conversation: Conversation | undefined,
+  detail: ConversationDetailReport | undefined,
+  tooltipPlacement?: "above" | "below",
+): ReactNode {
+  if (!conversation) return null;
+  const costSummary = summarizeCost(
+    detail?.cumulativeUsage ?? conversation.cumulativeUsage,
+  );
+  const auxiliaryCosts = detail?.auxiliaryCosts ?? conversation.auxiliaryCosts;
+  const live = (detail?.status ?? conversation.status) === "active";
+  if (!costSummary && !auxiliaryCosts && !live) return null;
+  return (
+    <CostMetric
+      auxiliaryCosts={auxiliaryCosts}
+      childAgentTotals={
+        detail?.childAgentTotals ?? conversation.childAgentTotals
+      }
+      live={live}
+      liveModelId={liveModelId(detail)}
+      modelUsage={detail?.modelUsage}
+      summary={costSummary}
+      tooltipPlacement={tooltipPlacement}
+    />
+  );
+}
+
 function conversationStatItems(props: {
   conversation: Conversation | undefined;
   detail?: ConversationDetailReport;
@@ -580,7 +611,6 @@ function conversationStatItems(props: {
     props.detail?.cumulativeUsage ?? props.conversation.cumulativeUsage;
   const tokenSummary =
     summarizeModelUsage(props.detail?.modelUsage) ?? summarizeUsage(usage);
-  const costSummary = summarizeCost(usage);
   const durationLabel = formatConversationDuration(props.conversation);
   const live = (props.detail?.status ?? props.conversation.status) === "active";
   const activeModelId = liveModelId(props.detail);
@@ -589,8 +619,9 @@ function conversationStatItems(props: {
     props.detail?.childAgentTotals ?? props.conversation.childAgentTotals;
   const lastActivityAt = props.conversation.lastSeenAt;
   const location = conversationLocation(props.conversation, props.detail);
+  const cost = conversationCost(props.conversation, props.detail);
   const rawStats: Array<ConversationStatItem | undefined> = [
-    // The desktop title bar shows the location. Mobile hides that bar.
+    // The desktop title bar shows the location and cost. Mobile hides that bar.
     location
       ? {
           content: location,
@@ -660,26 +691,12 @@ function conversationStatItems(props: {
           label: "Tokens",
         }
       : undefined,
-    costSummary ||
-    props.detail?.auxiliaryCosts ||
-    props.conversation.auxiliaryCosts ||
-    live
+    cost
       ? {
-          content: (
-            <CostMetric
-              auxiliaryCosts={
-                props.detail?.auxiliaryCosts ??
-                props.conversation.auxiliaryCosts
-              }
-              childAgentTotals={childAgentTotals}
-              live={live}
-              liveModelId={activeModelId}
-              modelUsage={props.detail?.modelUsage}
-              summary={costSummary}
-            />
-          ),
+          content: cost,
           key: "cost",
           label: "Cost",
+          mobileOnly: true,
         }
       : undefined,
     childAgentTotals
diff --git a/packages/junior-dashboard/src/client/conversations/ConversationPage.tsx b/packages/junior-dashboard/src/client/conversations/ConversationPage.tsx
index 7b20e38bad..4ae43473d8 100644
--- a/packages/junior-dashboard/src/client/conversations/ConversationPage.tsx
+++ b/packages/junior-dashboard/src/client/conversations/ConversationPage.tsx
@@ -50,6 +50,7 @@ import { ConversationAgentTree } from "./ConversationAgentTree";
 import { conversationLinks } from "./ConversationLinkedWork";
 import {
   ConversationAnnotations,
+  conversationCost,
   conversationLocation,
   ConversationPrivacyChip,
   ConversationStats,
@@ -373,6 +374,7 @@ export function ConversationPage(props: {
               agentTree ? <ConversationAgentTree nodes={agentTree} /> : null
             }
             conversationId={conversationId}
+            cost={conversationCost(conversation, detail.data, "below")}
             detailsOpen={showDetails}
             onDetailsClick={() => {
               if (eventOpen) setSelectedEventSeq(undefined);
diff --git a/packages/junior-dashboard/src/client/conversations/TelemetryMetrics.tsx b/packages/junior-dashboard/src/client/conversations/TelemetryMetrics.tsx
index 35935b1e9b..3d6b48bd3e 100644
--- a/packages/junior-dashboard/src/client/conversations/TelemetryMetrics.tsx
+++ b/packages/junior-dashboard/src/client/conversations/TelemetryMetrics.tsx
@@ -350,6 +350,7 @@ export function CostMetric(props: {
   liveModelId?: string;
   modelUsage?: ConversationModelUsage[];
   summary: CostUsageSummary | undefined;
+  tooltipPlacement?: "above" | "below";
 }) {
   // Model history can include calls not yet counted in saved Run totals.
   const summary = summarizeModelCost(props.modelUsage) ?? props.summary;
@@ -369,7 +370,7 @@ export function CostMetric(props: {
   return (
     <MetricValue
       align={props.align}
-      tooltipPlacement="above"
+      tooltipPlacement={props.tooltipPlacement ?? "above"}
       tooltip={
         !card && props.liveModelId
           ? [modelHeading(props.liveModelId, props.liveModelId)]
diff --git a/packages/junior-dashboard/src/client/conversations/UsageCard.tsx b/packages/junior-dashboard/src/client/conversations/UsageCard.tsx
index 2d322dbf71..48977b604b 100644
--- a/packages/junior-dashboard/src/client/conversations/UsageCard.tsx
+++ b/packages/junior-dashboard/src/client/conversations/UsageCard.tsx
@@ -66,13 +66,13 @@ export function UsageCard(props: UsageCardProps) {
         )}
       >
         <span className="flex items-baseline justify-between gap-3">
-          <span className="min-w-0 truncate">
+          <span className="min-w-0 truncate font-medium text-dashboard-text">
             {props.title}
             {props.note ? (
               <span className="text-dashboard-text-faint"> · {props.note}</span>
             ) : null}
           </span>
-          <span className="whitespace-nowrap text-lg font-semibold tabular-nums text-dashboard-text">
+          <span className="whitespace-nowrap text-base font-semibold tabular-nums text-dashboard-text">
             {props.total}
           </span>
         </span>
@@ -124,7 +124,7 @@ export function UsageCard(props: UsageCardProps) {
               <span
                 className={cn(
                   "flex min-w-0 items-baseline gap-2",
-                  row.code && "font-mono text-dashboard-text",
+                  row.code && "font-mono",
                 )}
               >
                 <span className="min-w-0 truncate" title={row.label}>