CHA₂DS₂-VASc Score Calculator
Calculate the CHA₂DS₂-VASc score for stroke risk stratification in atrial fibrillation patients.
About this calculator
CHA₂DS₂-VASc estimates annual ischemic stroke risk in patients with atrial fibrillation by summing eight clinical risk factors, unevenly weighted: congestive heart failure, hypertension, diabetes, vascular disease, age 65-74, and female sex each add 1 point, while age 75 or older and a prior stroke, TIA, or thromboembolism each add 2 points -- reflecting that age and prior thromboembolism carry roughly double the stroke risk of the other factors. The resulting 0-9 total maps to a published annual stroke risk table from Lip et al.'s Euro Heart Survey analysis (Chest, 2010): risk climbs from 0% at a score of 0 to 15.2% at a score of 9, though the table is not perfectly monotonic in its upper range -- the published rates for scores 7 and 8 (9.6% and 6.7%) sit slightly below score 6 (9.8%), a real artifact of how few patients in the original cohort reached those high scores, not a calculation error.
A score of 0 in a man, or 1 in a woman (since female sex alone contributes a point without representing independent stroke risk), typically needs no anticoagulation; a score of 1 in a man or 2 in a woman prompts considering it; higher scores generally warrant anticoagulation, following current AF guideline thresholds. This calculator does not weigh bleeding risk (see a HAS-BLED score for that) or account for anticoagulant contraindications, both of which a full anticoagulation decision requires alongside CHA₂DS₂-VASc.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.
Inputs
Results
CHA₂DS₂-VASc Score
0/ 9
Annual Stroke Risk
0%
Figures current as of 2010. Source: Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJGM. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation. Chest. 2010;137(2):263-272.
How to Use This Calculator
- Enter 0 or 1 for CHF, hypertension, diabetes, prior stroke/TIA, and vascular disease; select the age band (under 65 / 65-74 / 75+) and sex.
- Review CHA₂DS₂-VASc Score and annual stroke risk (%).
- Score ≥ 2 (men) or ≥ 3 (women) generally warrants anticoagulation in atrial fibrillation.
What each input means
- Congestive Heart Failure
- History of CHF or LV dysfunction (+1 point).
- Hypertension
- Resting BP >140/90 or on antihypertensives (+1 point).
- Diabetes Mellitus
- Fasting glucose >125 or on treatment (+1 point).
- Prior Stroke/TIA/Thromboembolism
- Previous stroke, TIA, or systemic embolism (+2 points).
- Vascular Disease
- Prior MI, PAD, or aortic plaque (+1 point).
- Age
- Age band: under 65 (+0 points), 65-74 (+1 point), 75 or older (+2 points). A single select so the impossible "both 65-74 and 75+" combination can't be entered.
- Sex
- Biological sex (+1 point for female).
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersCongestive Heart Failure = 0, Hypertension = 0, Age Band = 0, Diabetes Mellitus = 0 = 7 input(s) provided
- Calculate CHA₂DS₂-VASc ScoreCHA₂DS₂-VASc Score0 = 0
- Calculate Annual Stroke RiskAnnual Stroke Risk0 = 0%
- Calculate Anticoag. RecommendationAnticoag. Recommendation0 = 0
Figures and sources
- CHA₂DS₂-VASc score (stroke risk in atrial fibrillation) (2010) — Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJGM. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation. Chest. 2010;137(2):263-272.
Engine last updated . Checked against 5 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why do age ≥75 and prior stroke/TIA count for 2 points while the other risk factors only count 1?
CHA₂DS₂-VASc is not an equal-weight checklist. Being 75 or older and having a prior stroke, TIA, or systemic embolism are each independently associated with roughly double the stroke risk of the other listed factors -- congestive heart failure, hypertension, diabetes, vascular disease, age 65-74, and female sex -- so those two factors are scored 2 points each while the rest are scored 1 point each.
Why does the annual stroke risk table jump around instead of rising smoothly at scores 7 and 8?
The published risk figures (0% at score 0 rising to 15.2% at score 9) come from a 1,084-patient cohort in Lip et al.'s 2010 Euro Heart Survey analysis, and very few patients in that cohort actually reached scores of 7 or 8. That small sample size at the high end produces published rates (9.6% at 7, 6.7% at 8) that dip slightly below the 9.8% rate reported at a score of 6 -- a real feature of the source data, not an error in this calculator.
Does a CHA₂DS₂-VASc score of 1 always mean the same anticoagulation recommendation?
No, and this is a common point of confusion. Female sex alone contributes 1 point to the score without being an independent stroke-risk factor on its own -- it is a risk modifier that matters only in combination with other factors. In practice that means a score of 1 driven purely by female sex is typically treated more like a score of 0 for anticoagulation decisions, while a score of 1 from any other single factor supports considering anticoagulation. This calculator reports the raw total; the sex-specific nuance is a clinical judgment layered on top.
Is CHA₂DS₂-VASc enough on its own to decide whether to start anticoagulation?
No. CHA₂DS₂-VASc estimates stroke risk without atrial fibrillation treatment, but the decision to anticoagulate also requires weighing bleeding risk -- commonly assessed with a separate tool like HAS-BLED -- along with patient-specific contraindications, drug interactions, and preferences. A high CHA₂DS₂-VASc score supports anticoagulation but does not by itself account for the bleeding side of that tradeoff.
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