CHA2DS2-VASc Score Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/9/2026
The CHA2DS2-VASc score adds points for each risk factor present (heart failure, hypertension, age, diabetes, prior stroke, vascular disease, female sex), for a total from 0 to 9. A score of 0 corresponds to a low stroke risk, while a high score points toward anticoagulation.
Explanation
The CHA2DS2-VASc score is the reference clinical tool for estimating the annual risk of stroke or systemic embolism in a patient with atrial fibrillation, the most common heart rhythm disorder in cardiology. It adds up points assigned to each cardiovascular risk factor present: congestive heart failure, hypertension, diabetes, vascular disease (prior myocardial infarction, peripheral artery disease, or aortic plaque), and female sex each count for 1 point; a history of stroke, transient ischemic attack (TIA), or thromboembolism counts double, at 2 points, reflecting its particularly high weight in recurrence risk; age is scored by bracket, from 0 points under 65 to 2 points at 75 or older, with 1 point between 65 and 74. The total score, ranging from 0 to 9, guides the anticoagulation decision: a score of 0 corresponds to low risk generally not warranting anticoagulation, a score of 1 to moderate risk, and a score of 2 or more in men (3 or more in women, the difference accounting for the automatic point given for female sex) is the usual threshold where anticoagulation is generally recommended to reduce stroke risk. This score has largely replaced the older CHADS2 score, simpler but less precise, by adding three extra criteria (vascular disease, the 65-74 age bracket, female sex) that improve identification of genuinely low-risk patients. The anticoagulation decision nonetheless remains individualized by a cardiologist, who weighs it against each patient's own bleeding risk, generally assessed with a separate score (like the HAS-BLED score) — the hypertension factored into this score can be checked directly with our blood pressure calculator, while an abnormally fast or slow resting heart rate, another cardiovascular sign worth watching, shows up in our resting heart rate calculator.
Example: a woman aged 75 or older with a history of stroke
Inputs
Age: 75 or older (2 points). History of stroke: yes (2 points). Sex: female (1 point). No other factors.
Calculation
Total score = 2 (age) + 2 (stroke) + 1 (female sex) = 5.
Result
This score of 5 corresponds to a high stroke risk, generally above the threshold recommending anticoagulation.
Frequently asked questions
Why does a history of stroke count double compared to other factors?
Because a history of stroke, TIA, or thromboembolism is the risk factor most strongly associated with a recurrent cerebrovascular event among all those included in this score: the studies used to establish and validate the CHA2DS2-VASc score showed that this factor weighs about twice as much as the other criteria in predicting actual annual risk.
Why does female sex add a point?
The epidemiological studies that led to developing the CHA2DS2-VASc score showed a slightly higher stroke risk in women with atrial fibrillation compared to men, with otherwise identical risk factors, which justified adding this point compared to the older CHADS2 score, which didn't include it. This is also what explains the slightly different anticoagulation threshold between men and women (2 versus 3).
Does a high CHA2DS2-VASc score automatically mean anticoagulant treatment?
No, this score strongly guides the decision but doesn't determine it alone: a cardiologist always weighs this stroke risk against the patient's own bleeding risk, often assessed with a separate score like HAS-BLED, before deciding on anticoagulation. This calculator is a clinical decision-support tool, never a substitute for this individualized assessment by a healthcare professional.