diff --git a/src/modules/mileage/StatisticsView.tsx b/src/modules/mileage/StatisticsView.tsx
index cbd3b27..fd8fa9c 100644
--- a/src/modules/mileage/StatisticsView.tsx
+++ b/src/modules/mileage/StatisticsView.tsx
@@ -12,6 +12,7 @@ import {
 import type { TargetSummary, TargetVehicle, TargetYearlyAssessment, TrendPoint } from './types';
 import { fetchTargets, fetchTargetVehicles, fetchTrend } from './api';
 import Blur from '../../components/Blur';
+import { weightedCompletionRate } from '../../shared/analytics/metrics';
 
 function getDefaultDate(): string {
   const now = new Date();
@@ -83,6 +84,12 @@ export default function StatisticsView() {
   const selectedDaysLeft = selectedAssessment?.daysLeft ?? selectedTarget?.daysLeft ?? 0;
   const selectedDailyTarget = selectedAssessment?.dailyTarget ?? (selectedDaysLeft > 0 ? selectedRemaining / selectedDaysLeft : 0);
   const selectedQualifiedRate = selectedAssessment?.qualifiedRate ?? (selectedTarget?.vehicleCount ? selectedTarget.yearQualifiedCount / selectedTarget.vehicleCount * 100 : 0);
+  const selectedYearCompletionRate = weightedCompletionRate(
+    targets.flatMap(target => {
+      const assessment = getTargetAssessment(target, assessmentYearMap[target.id]);
+      return assessment ? [{ completed: assessment.completed, target: assessment.target }] : [];
+    }),
+  );
   const latestTrend = trendData[trendData.length - 1];
   const previousTrend = trendData[trendData.length - 2];
   const trendDelta = latestTrend && previousTrend ? latestTrend.mileage - previousTrend.mileage : 0;
@@ -541,7 +548,7 @@ export default function StatisticsView() {
                   <span className="text-slate-700">|</span>
                   <span className="text-slate-500">车辆 <span className="text-white font-black">{targets.reduce((sum, t) => sum + t.vehicleCount, 0)}</span> 台</span>
                   <span className="text-slate-700">|</span>
-                  <span className="text-slate-500">所选年度完成率 <span className="text-white font-black">{targets.length > 0 ? (targets.reduce((sum, t) => sum + (getTargetAssessment(t, assessmentYearMap[t.id])?.completionRate ?? t.avgCompletion), 0) / targets.length).toFixed(1) : '0.0'}</span> <span className="text-blue-400">%</span></span>
+                  <span className="text-slate-500">所选年度完成率 <span className="text-white font-black">{selectedYearCompletionRate.toFixed(1)}</span> <span className="text-blue-400">%</span></span>
                 </div>
               </div>
               <div className="flex items-center gap-2">
diff --git a/src/shared/analytics/metrics.test.ts b/src/shared/analytics/metrics.test.ts
new file mode 100644
index 0000000..dd6ab58
--- /dev/null
+++ b/src/shared/analytics/metrics.test.ts
@@ -0,0 +1,30 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { weightedCompletionRate } from './metrics.js';
+
+test('weights completion by target mileage', () => {
+  const result = weightedCompletionRate([
+    { completed: 100, target: 100 },
+    { completed: 0, target: 900 },
+  ]);
+
+  assert.equal(result, 10);
+});
+
+test('allows completion above 100 percent', () => {
+  const result = weightedCompletionRate([
+    { completed: 120, target: 100 },
+  ]);
+
+  assert.equal(result, 120);
+});
+
+test('ignores invalid and zero targets', () => {
+  const result = weightedCompletionRate([
+    { completed: 50, target: 0 },
+    { completed: Number.NaN, target: 100 },
+    { completed: 30, target: 60 },
+  ]);
+
+  assert.equal(result, 50);
+});
diff --git a/src/shared/analytics/metrics.ts b/src/shared/analytics/metrics.ts
new file mode 100644
index 0000000..230af0d
--- /dev/null
+++ b/src/shared/analytics/metrics.ts
@@ -0,0 +1,18 @@
+export interface ProgressMeasure {
+  completed: number;
+  target: number;
+}
+
+export function weightedCompletionRate(measures: ProgressMeasure[]): number {
+  let completed = 0;
+  let target = 0;
+
+  for (const measure of measures) {
+    if (!Number.isFinite(measure.target) || measure.target <= 0) continue;
+    if (!Number.isFinite(measure.completed)) continue;
+    completed += Math.max(0, measure.completed);
+    target += measure.target;
+  }
+
+  return target > 0 ? completed / target * 100 : 0;
+}