diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/header.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/header.tsx
index bfdbfa51b5e..a744a49d613 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/header.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/header.tsx
@@ -54,7 +54,10 @@ export function Header() {
     const model = sync.data.provider.find((x) => x.id === last.providerID)?.models[last.modelID]
     let result = total.toLocaleString()
     if (model?.limit.context) {
-      result += "  " + Math.round((total / model.limit.context) * 100) + "%"
+      const pct = Math.round((total / model.limit.context) * 100)
+      if (!isNaN(pct) && isFinite(pct)) {
+        result += "  " + pct + "%%"
+      }
     }
     return result
   })
diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
index 6c74e04fac7..93a1cf1ffc6 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/sidebar.tsx
@@ -43,9 +43,10 @@ export function Sidebar(props: { sessionID: string }) {
     const total =
       last.tokens.input + last.tokens.output + last.tokens.reasoning + last.tokens.cache.read + last.tokens.cache.write
     const model = sync.data.provider.find((x) => x.id === last.providerID)?.models[last.modelID]
+    const pct = model?.limit.context ? Math.round((total / model.limit.context) * 100) : null
     return {
       tokens: total.toLocaleString(),
-      percentage: model?.limit.context ? Math.round((total / model.limit.context) * 100) : null,
+      percentage: pct !== null && !isNaN(pct) && isFinite(pct) ? pct : 0,
     }
   })
 
@@ -82,7 +83,7 @@ export function Sidebar(props: { sessionID: string }) {
                 <b>Context</b>
               </text>
               <text fg={theme.textMuted}>{context()?.tokens ?? 0} tokens</text>
-              <text fg={theme.textMuted}>{context()?.percentage ?? 0}% used</text>
+              <text fg={theme.textMuted}>{context()?.percentage ?? 0}%% used</text>
               <text fg={theme.textMuted}>{cost()} spent</text>
             </box>
             <Show when={mcpEntries().length > 0}>