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. It is designed for clinicians, medical students, evidence-synthesis researchers. The 8 items are combined to produce a total score.
CHA2DS2-VASc contains 8 items. Item scores are combined with weighted scoring to produce the total. Scores run from 0 to 9, grouped into 3 interpretation bands from ‘Low risk’ up to ‘High risk’.
On the CHA2DS2-VASc (total score 0–9), scores of 2–9 fall in the ‘High risk’ band — interpreted as: High stroke risk. Anticoagulation recommended. The full ladder is: 0 — Low risk: Low stroke risk. Anticoagulation usually not needed.; 1 — Borderline: Borderline. Discuss anticoagulation with your team.; 2–9 — High risk: High stroke risk. Anticoagulation recommended. A higher score reflects a more severe presentation, and crossing a cutoff is a prompt to step up assessment or care — but these bands are screening thresholds, not diagnoses.
Scores of 0 fall in the ‘Low risk’ band: Low stroke risk. Anticoagulation usually not needed. A low score is reassuring but does not by itself rule out the underlying condition — if symptoms or clinical suspicion persist, reassess over time or use a complementary evaluation rather than relying on the number alone.
Yes — CHA2DS2-VASc is in the public domain and free for clinical, educational, and research use without permission. You can use this calculator and the scale itself freely; if you publish results or reproduce the scale, cite the original source paper.
Lip GY et al. Chest. 2010;137(2):263-272. This is the original publication for the CHA2DS2-VASc — the reference to cite when reporting results.
No. CHA2DS2-VASc is a structured assessment aid, not a diagnostic test. Its proper role is clinical assessment of annual stroke risk in non-valvular atrial fibrillation — it standardizes assessment and flags who needs closer evaluation, but the result must be weighed alongside history, examination, and clinical context. When a score conflicts with your clinical impression, clinical judgment takes precedence; treatment decisions should never rest on a screening score alone.
CHA2DS2-VASc is supported by the following peer-reviewed sources: