CHA₂DS₂-VASc Stroke Risk Calculator

What Is CHA₂DS₂-VASc?

The CHA₂DS₂-VASc score is a clinical scoring system used to estimate the risk of stroke in patients with non-valvular atrial fibrillation (AFib).
AFib is the most common sustained heart rhythm disorder, affecting about 60 million people worldwide by the Global Burden of Disease 2019 estimate.
Without treatment, AFib increases stroke risk by 5-fold compared to the general population.
The score was developed in 2010 by Lip and colleagues and became the international standard. The 2023 American (ACC/AHA/ACCP/HRS) guideline still uses it. The 2024 European (ESC) guideline dropped the sex point and uses CHA₂DS₂-VA instead, which this calculator also shows.

Score Components

C, Congestive heart failure (1 point): recent decompensated heart failure or reduced ejection fraction.
H, Hypertension (1 point): persistent BP above 140/90 mmHg or on antihypertensive medication.
A₂, Age ≥ 75 years (2 points): higher weighting due to exponentially higher stroke risk.
D, Diabetes mellitus (1 point): type 1 or type 2 diabetes on medication.
S₂, Prior Stroke / TIA / Thromboembolism (2 points): the strongest independent risk factor.
V, Vascular disease (1 point): prior MI, peripheral artery disease, or aortic plaque.
A, Age 65–74 years (1 point): the two age criteria are alternatives, never both. A patient of 78 scores 2 for A₂ and nothing for A, which is why the calculator asks for one age band rather than two yes-or-no questions.
Sc, Sex category female (1 point): biological females have higher baseline stroke risk in AFib.

Annual Stroke Risk by Score

These are the adjusted annual stroke rates from the 2010 validation, the table reproduced in the European guidelines:

A caveat on those percentages. They do not climb cleanly at the top: score 7 sits just under score 6, and score 8 drops back to 6.7%, because very few patients in the cohort scored that high. Read anything at 7 or above as very high risk rather than reading the exact figure. At the bottom the table is probably too high. Friberg and colleagues’ 2015 study of 140,420 untreated Swedish patients found men with a score of 1 had a stroke rate of only about 0.5 to 0.7% a year, which is why a score of 1 is a judgement call rather than an automatic prescription.

Treatment Guidelines

Thresholds are read on the score excluding the sex point, because being female is not on its own an indication for anticoagulation. A woman with a score of 1 from sex alone is treated as a 0. That is exactly what the 2024 ESC guideline formalised by dropping the point altogether: its CHA₂DS₂-VA is this score without the Sc.
Score 0 after that exclusion: no anticoagulation.
Score 1: consider anticoagulation. This is the band where the decision genuinely turns on bleeding risk and patient preference rather than on the number.
Score 2 or more: oral anticoagulation recommended, with a DOAC (apixaban, rivaroxaban, dabigatran, edoxaban) preferred in non-valvular AFib.
The 2023 American guideline puts the line as an annual stroke risk of 2% or more, which it equates with CHA₂DS₂-VASc 2 or more in men and 3 or more in women. Same line, written the other way.
Warfarin remains an option but requires more monitoring (INR target 2.0–3.0).
Stroke risk is only half the decision. Bleeding risk, usually scored with HAS-BLED, is the other half, and a high bleeding score is a reason to correct modifiable risk factors rather than to withhold treatment.

Important Disclaimer

This calculator provides a general estimate for educational purposes only.
It is NOT a substitute for clinical evaluation by a licensed healthcare professional.