Not for clinical use. This calculator supports clinical decisions (dosing, a risk score, an obstetric or laboratory assessment) and has not been reviewed by a named qualified clinician. It is published for reference and education only, it is excluded from search indexing for that reason, and it must not be used to guide the care of any patient. Verify every figure against the primary source and your own professional judgement.
CHA2DS2-VASc Score Calculator
The CHA2DS2-VASc score estimates the risk of stroke in people with non-valvular atrial fibrillation and helps guide decisions about anticoagulation. It assigns points for congestive heart failure, hypertension, age, diabetes, prior stroke, vascular disease, and sex. This tool totals the points; the decision to anticoagulate is clinical and considers bleeding risk as well.
CHA2DS2-VASc points
C: congestive heart failure = 1
H: hypertension = 1
A2: age 75 or older = 2, age 65 to 74 = 1
D: diabetes = 1
S2: prior stroke, TIA, or thromboembolism = 2
V: vascular disease = 1
Sc: female sex = 1
Score = sum of all points (range 0 to 9)
Each risk factor contributes its points; stroke history and age 75 or older are each worth two points. The maximum score is 9. Higher scores indicate higher estimated annual stroke risk.
Worked example
A 70-year-old woman with hypertension and diabetes, no heart failure, no prior stroke, and no vascular disease scores: age 65 to 74 (+1) + hypertension (+1) + diabetes (+1) + female (+1) = 4. Guidelines generally favour anticoagulation at scores of 2 or more in men and 3 or more in women, but this is a clinical decision.
Frequently asked questions
What score means anticoagulation is recommended?
Guidelines commonly recommend considering anticoagulation at a score of 2 or more in men and 3 or more in women, with shared decision-making at lower scores. This tool reports the score only; the treatment decision is clinical and weighs bleeding risk.
Why does female sex add a point?
Female sex is a stroke risk modifier in atrial fibrillation in the original scoring system, generally relevant when at least one other risk factor is present. The point is included as defined by the published score.
Is this for valvular atrial fibrillation?
No. CHA2DS2-VASc is validated for non-valvular atrial fibrillation. Valvular atrial fibrillation, such as with moderate to severe mitral stenosis or a mechanical valve, generally warrants anticoagulation regardless of score.
Does it estimate bleeding risk?
No. It estimates stroke risk only. Bleeding risk is assessed with separate tools and clinical judgement before starting anticoagulation.
Sources
- U.S. National Library of Medicine, StatPearls: CHA2DS2-VASc Score.
- U.S. National Heart, Lung, and Blood Institute: Atrial Fibrillation.
This content is provided for educational purposes only and has not been reviewed by a qualified specialist in this field. Educational tool, not medical advice. See our methodology.