diff --git a/backend/app/routers/study_tools.py b/backend/app/routers/study_tools.py
index ae8934a..15aa733 100644
--- a/backend/app/routers/study_tools.py
+++ b/backend/app/routers/study_tools.py
@@ -11,6 +11,7 @@ from app.database import get_db
 from app.models.attempt import AttemptAnswer, QuizAttempt
 from app.models.lab_reference import LabReference
 from app.models.question import Question
+from app.models.question_category import QuestionCategory, QuestionCategoryLink
 from app.models.quiz import Quiz
 from app.models.user import User
 from app.utils.auth import get_current_user, require_moderator
@@ -101,6 +102,44 @@ def delete_lab_value(entry_id: int, db: Session = Depends(get_db), user: User =
     db.commit()
 
 
+@router.get("/performance-by-category")
+def performance_by_category(db: Session = Depends(get_db), user: User = Depends(get_current_user)):
+    """Accuracy per category from the user's completed, non-expired general-bank answers.
+    A question counts in its primary category and every additional category link."""
+    from collections import defaultdict
+    from app.models.question_category import QuestionCategoryLink
+    rows = db.query(AttemptAnswer.question_id, AttemptAnswer.is_correct, Question.question_category_id).join(
+        QuizAttempt, QuizAttempt.id == AttemptAnswer.attempt_id).join(Quiz, Quiz.id == QuizAttempt.quiz_id).join(
+        Question, Question.id == AttemptAnswer.question_id).filter(
+        QuizAttempt.user_id == user.id, QuizAttempt.completed_at.isnot(None),
+        or_(QuizAttempt.expired == 0, QuizAttempt.expired.is_(None)), Quiz.course_id.is_(None),
+    ).all()
+    extra: dict[int, set[int]] = defaultdict(set)
+    for qid, cid in db.query(QuestionCategoryLink.question_id, QuestionCategoryLink.category_id).all():
+        extra[qid].add(cid)
+    counts: dict[int, list[int]] = defaultdict(lambda: [0, 0])
+    for qid, is_correct, primary in rows:
+        categories = extra.get(qid, set()) | ({primary} if primary else set())
+        for cid in categories:
+            counts[cid][0] += 1
+            if is_correct:
+                counts[cid][1] += 1
+    names = {cat.id: cat.name for cat in db.query(QuestionCategory).all()}
+    categories = [{
+        "category_id": cid,
+        "name": names.get(cid, "Uncategorized"),
+        "answered": answered,
+        "correct": correct,
+        "accuracy": round(100 * correct / answered, 1) if answered else 0,
+    } for cid, (answered, correct) in counts.items()]
+    categories.sort(key=lambda row: (-row["answered"], row["name"]))
+    return {
+        "total_answered": sum(row["answered"] for row in categories),
+        "categories": categories,
+        "basis": "Your completed, non-expired general test answers; a question counts in every category it belongs to.",
+    }
+
+
 @router.get("/attempts/{attempt_id}/questions/{question_id}/responses")
 def question_responses(attempt_id: int, question_id: int, db: Session = Depends(get_db), user: User = Depends(get_current_user)):
     attempt = db.query(QuizAttempt).filter_by(id=attempt_id, user_id=user.id).first()
diff --git a/backend/tests/test_study_tools.py b/backend/tests/test_study_tools.py
index 2f14f3d..f52cb64 100644
--- a/backend/tests/test_study_tools.py
+++ b/backend/tests/test_study_tools.py
@@ -151,6 +151,24 @@ class StudyToolTests(unittest.TestCase):
         response = self.client.get(f'/study-tools/attempts/{peer_study}/questions/1/responses').json()
         self.assertEqual(response['sample_size'], 0)
 
+    def test_performance_by_category_expands_links_and_excludes_irrelevant(self):
+        quiz = self.bank.generate(is_shared=True, category_ids=[1]).json()['id']
+        self.bank.answer(1, True, quiz_id=quiz)
+        self.bank.answer(1, True, quiz_id=quiz, expired=1)  # Expired attempt excluded.
+        quiz2 = self.bank.generate(is_shared=True, category_ids=[2], count=1).json()['id']
+        self.bank.answer(2, False, quiz_id=quiz2)
+        self.client.patch('/questions/3', json={'additional_category_ids': [2]})  # Owner edits own question.
+        quiz3 = self.bank.generate(category_ids=[3], count=1).json()['id']  # Private owner test: own attempts still count.
+        self.bank.answer(3, True, quiz_id=quiz3)
+        self.bank.answer(5, True, quiz_id=2)  # Course quiz excluded.
+        data = self.client.get('/study-tools/performance-by-category').json()
+        by_id = {row['category_id']: row for row in data['categories']}
+        self.assertEqual([by_id[1]['answered'], by_id[1]['correct'], by_id[1]['accuracy']], [1, 1, 100.0])
+        self.assertEqual([by_id[2]['answered'], by_id[2]['correct'], by_id[2]['accuracy']], [2, 1, 50.0])
+        self.assertEqual([by_id[3]['answered'], by_id[3]['correct']], [1, 1])
+        self.assertEqual(data['total_answered'], 4)
+        self.assertEqual(data['categories'][0]['category_id'], 2)  # Most answered first.
+
     def test_lab_reference_permissions_validation_and_publication(self):
         payload = dict(name='Example test', group='Blood', reference_range='Example interval', units='example units',
                        age_group='Defined study population', specimen='Serum', source='Educator-supplied source', source_url='https://example.test/reference')
diff --git a/frontend/src/components/CategoryPerformance.jsx b/frontend/src/components/CategoryPerformance.jsx
new file mode 100644
index 0000000..8ec2bf6
--- /dev/null
+++ b/frontend/src/components/CategoryPerformance.jsx
@@ -0,0 +1,26 @@
+import { useEffect, useState } from 'react'
+import api from '../api/client'
+
+export default function CategoryPerformance() {
+  const [data, setData] = useState(null)
+  useEffect(() => {
+    api.get('/study-tools/performance-by-category')
+      .then(res => setData(res.data))
+      .catch(() => setData(null))
+  }, [])
+  if (!data || !data.categories?.length) return null
+  return (
+    <div className="card" data-testid="category-performance">
+      <h2 style={{ margin: '0 0 4px' }}>Performance by category</h2>
+      <p style={{ color: 'var(--text-muted)', fontSize: '0.8rem', margin: '0 0 14px' }}>{data.basis}</p>
+      {data.categories.map(category => (
+        <div className="category-performance-row" key={category.category_id}>
+          <span className="cp-name">{category.name}</span>
+          <span className="cp-track"><span className="cp-fill" style={{ width: `${category.accuracy}%` }} /></span>
+          <span className="cp-accuracy">{category.accuracy}%</span>
+          <span className="cp-count">{category.correct}/{category.answered}</span>
+        </div>
+      ))}
+    </div>
+  )
+}
diff --git a/frontend/src/components/CategoryPerformance.test.jsx b/frontend/src/components/CategoryPerformance.test.jsx
new file mode 100644
index 0000000..af661b7
--- /dev/null
+++ b/frontend/src/components/CategoryPerformance.test.jsx
@@ -0,0 +1,36 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { render, screen, waitFor } from '@testing-library/react'
+import CategoryPerformance from './CategoryPerformance'
+import api from '../api/client'
+
+vi.mock('../api/client', () => ({ default: { get: vi.fn() } }))
+
+beforeEach(() => { vi.resetAllMocks() })
+
+describe('category performance', () => {
+  it('renders accuracy rows with counts and the stated basis', async () => {
+    api.get.mockResolvedValue({ data: {
+      total_answered: 3,
+      basis: 'Your completed, non-expired general test answers.',
+      categories: [
+        { category_id: 2, name: 'Clinical reasoning', answered: 2, correct: 1, accuracy: 50 },
+        { category_id: 1, name: 'Pediatrics', answered: 1, correct: 1, accuracy: 100 },
+      ],
+    } })
+    render(<CategoryPerformance />)
+    expect(await screen.findByTestId('category-performance')).toBeInTheDocument()
+    expect(screen.getByText('Clinical reasoning')).toBeInTheDocument()
+    expect(screen.getByText('50%')).toBeInTheDocument()
+    expect(screen.getByText('1/2')).toBeInTheDocument()
+    expect(screen.getByText('100%')).toBeInTheDocument()
+    expect(screen.getByText(/completed, non-expired/)).toBeInTheDocument()
+  })
+
+  it('renders nothing without category data', async () => {
+    api.get.mockResolvedValue({ data: { total_answered: 0, categories: [] } })
+    const { container } = render(<CategoryPerformance />)
+    await waitFor(() => expect(api.get).toHaveBeenCalled())
+    await new Promise(resolve => setTimeout(resolve, 0))
+    expect(container.querySelector('[data-testid="category-performance"]')).toBeNull()
+  })
+})
diff --git a/frontend/src/index.css b/frontend/src/index.css
index 47f5b9a..b33406e 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -735,3 +735,14 @@ body {
 .lesson-content code { background: var(--bg); padding: 2px 6px; border-radius: 4px; font-size: 0.88em; }
 .lesson-content pre { background: var(--bg); padding: 12px 16px; border-radius: 8px; overflow-x: auto; }
 .lesson-content strong { font-weight: 700; }
+.category-performance-row { display: grid; grid-template-columns: minmax(120px, 1fr) minmax(80px, 2fr) 64px 84px; gap: 10px; align-items: center; padding: 8px 0; border-bottom: 1px solid var(--border); font-size: .86rem; }
+.category-performance-row:last-child { border-bottom: none; }
+.cp-name { font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.cp-track { height: 8px; background: var(--bg, #e2e8f0); border-radius: 999px; overflow: hidden; display: block; }
+.cp-fill { display: block; height: 100%; background: var(--primary, #2563eb); border-radius: 999px; }
+.cp-accuracy { font-weight: 700; text-align: right; }
+.cp-count { color: var(--text-muted); text-align: right; }
+@media (max-width: 560px) {
+  .category-performance-row { grid-template-columns: 1fr 56px; }
+  .cp-track { grid-column: 1 / -1; grid-row: 2; }
+}
diff --git a/frontend/src/pages/DashboardPage.jsx b/frontend/src/pages/DashboardPage.jsx
index 5757f8d..859be95 100644
--- a/frontend/src/pages/DashboardPage.jsx
+++ b/frontend/src/pages/DashboardPage.jsx
@@ -3,6 +3,7 @@ import { Link } from 'react-router-dom'
 import api from '../api/client'
 import LineChart from '../components/LineChart'
 import InProgressQuizzes from '../components/InProgressQuizzes'
+import CategoryPerformance from '../components/CategoryPerformance'
 import MyNote from '../components/MyNote'
 import { useAuth } from '../context/AuthContext'
 
@@ -78,6 +79,8 @@ export default function DashboardPage() {
 
       <InProgressQuizzes />
 
+      <CategoryPerformance />
+
       <MyNote variant="card" />
 
       {/* Performance graph with dropdown */}