Annual stroke risk in non-valvular atrial fibrillation. Free to use.
CHA2DS2-VASc (CHA2DS2-VASc Score for Stroke Risk in Atrial Fibrillation) is a validated clinical instrument used to assess annual stroke risk in non-valvular atrial fibrillation. The instrument contains 8 items.
Source / attribution: Lip GY et al., Chest 2010
The instrument's primary construct — annual stroke risk in non-valvular atrial fibrillation — is operationalized through a fixed set of items, each with a defined response format. This standardisation is what allows CHA2DS2-VASc scores to be compared meaningfully across clinicians, sites, and studies.
Like all screening or assessment instruments, CHA2DS2-VASc is a structured aid — not a diagnostic test in isolation. Results should be interpreted alongside history, examination, and clinical context. Where a score crosses an actionable threshold, the next step is typically a more detailed clinical evaluation rather than a definitive diagnosis.
Answer all 8 items below to see your CHA2DS2-VASc score and interpretation.
All scoring runs in your browser. No data is sent anywhere — close the tab and the answers are gone.
CHA2DS2-VASc uses weighted summation: each item carries a fixed weight that is added when the response indicates a positive finding.
Scoring notes: Educational use only. Not a substitute for clinical judgment.
The cutoffs below are drawn from the published validation literature. Always interpret in clinical context.
| Score range | Band | Interpretation |
|---|---|---|
| 0–0 | Low risk | Low stroke risk. Anticoagulation usually not needed. |
| 1–1 | Borderline | Borderline. Discuss anticoagulation with your team. |
| 2–9 | High risk | High stroke risk. Anticoagulation recommended. |
This is an illustrative walkthrough, not a real patient. Follow the same four steps with your own answers — or use the live calculator at the top of this page.
Mark each item Yes or No. Each "Yes" adds the item's weight; each "No" adds 0. The example below uses illustrative answers.
| # | Item | Example response | Score |
|---|---|---|---|
| 1 | Congestive heart failure / LV dysfunction | No | 0 |
| 2 | Hypertension | No | 0 |
| 3 | Age ≥ 75 years | No | 0 |
| 4 | Diabetes mellitus | No | 0 |
| 5 | Prior stroke / TIA / thromboembolism | No | 0 |
| 6 | Vascular disease (prior MI, PAD, aortic plaque) | No | 0 |
| 7 | Age 65–74 years | Yes | 1 |
| 8 | Female sex | No | 0 |
Add the weights from the items where you marked "Yes" (skip the "No" answers — they contribute 0).
0 + 0 + 0 + 0 + 0 + 0 + 1 + 0 = 1
Find the row in the interpretation table whose range contains your total:
Total = 1 falls between 1 and 1 → Borderline
Borderline. Consider anticoagulation; weigh bleeding risk.
A score is one input alongside history and examination. CHA2DS2-VASc supports clinical judgment — it does not replace it.
If CHA2DS2-VASc doesn't fit your context, related instruments in cardiology include:
| Scale | Measures | Items | Time |
|---|---|---|---|
| HAS-BLED | 1-year risk of major bleeding on oral anticoagulation | 9 | — |
| HEART Score | 6-week MACE risk in ED patients with chest pain | 5 | — |
| NYHA Functional Class | Functional capacity in heart failure | 1 | — |
| APGAR Score | Rapid assessment of newborn at 1 and 5 min | 5 | — |
| ASA Physical Status | Pre-operative health status | 1 | — |
| CURB-65 | 30-day mortality in community-acquired pneumonia | 5 | — |
| Glasgow Coma Scale | Level of consciousness after head injury | 3 | — |
| Katz ADL | Functional independence in basic ADLs | 6 | — |
CHA2DS2-VASc (CHA2DS2-VASc Score for Stroke Risk in Atrial Fibrillation) is a validated instrument that assesses annual stroke risk in non-valvular atrial fibrillation.
CHA2DS2-VASc contains 8 items.
Scores of 2–9 fall in the "High risk" band. High stroke risk. Anticoagulation recommended.
Scores of 0–0 fall in the "Low risk" band. Low stroke risk. Anticoagulation usually not needed.
Yes — CHA2DS2-VASc is in the public domain and free for clinical, educational, and research use without permission.
Lip GY et al. Chest. 2010;137(2):263-272.
No. CHA2DS2-VASc is a structured assessment aid. A score is one input alongside history, examination, and clinical context. Treatment decisions should never rest on a screening score alone.
CHA2DS2-VASc is supported by the following peer-reviewed sources: