CHA₂DS₂-VASc Score Calculator — Stroke Risk in Atrial Fibrillation

CHA₂DS₂-VASc is the guideline-endorsed score for estimating stroke and systemic thromboembolism risk in patients with non-valvular atrial fibrillation (AF). It was derived by Lip and colleagues in 2010 to refine the older CHADS₂ score, chiefly by better identifying patients who are genuinely at low risk. It is a simple additive score — there is no arithmetic beyond adding up the points.

The name is a mnemonic for the eight factors, two of which (the subscript “2”s) are worth two points:

• C — Congestive heart failure / LV dysfunction → 1
• H — Hypertension (or treated) → 1
• A₂ — Age ≥ 75 years → 2
• D — Diabetes mellitus → 1
• S₂ — Prior Stroke / TIA / thromboembolism → 2
• V — Vascular disease (prior MI, PAD, aortic plaque) → 1
• A — Age 65–74 years → 1 (mutually exclusive with A₂)
• Sc — Sex category female → 1

The total is score = C + H + A(age) + D + S + V + Sc, ranging from 0 to 9. Age is entered as a single control with three states, so the 65–74 (1 point) and ≥75 (2 point) bands can never both fire — a common source of hand-calculation error.

Each total maps to an adjusted annual stroke rate. The figures shown here come from Friberg 2012 (Swedish AF cohort, no antithrombotic therapy), a validation cohort of 182,678 AF patients, and describe risk with no antithrombotic therapy — the baseline that anticoagulation aims to reduce. Risk rises steeply with score, from roughly 0.2% at a score of 0 to about 12.2% at 9.

The anticoagulation recommendation follows the 2020 ESC Atrial Fibrillation Guidelines. Oral anticoagulation is recommended at a score of ≥ 2 in men and ≥ 3 in women, and should be considered at 1 in men and 2 in women. The one subtlety the tool gets right is the sex category: female sex adds a point, but a woman whose only point is sex (score 1) is managed as low risk with no anticoagulation. Sex acts as a risk modifier once at least one other factor is present, not as a standalone indication.

• Lip GYH, et al. Refining clinical risk stratification… the Euro Heart Survey on Atrial Fibrillation. Chest 2010;137:263–272 (original CHA₂DS₂-VASc derivation)
• Friberg L, Rosenqvist M, Lip GYH. Evaluation of risk stratification schemes… Swedish AF cohort. Eur Heart J 2012;33:1500–1510 (annual stroke rates by score)
• Hindricks G, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation. Eur Heart J 2021;42:373–498 (anticoagulation thresholds)

The point scheme, annual stroke rates and anticoagulation thresholds on this page were last cross-checked against these sources on 2026-07-12. This tool is for education and reference only; it does not provide medical advice and does not replace assessment by a qualified clinician.