CHA2DS2-VASc Calculator
Stroke-risk stratification for atrial fibrillation: score the risk factors, get the total, and see the published annual stroke-risk estimate for that score.
CHA2DS2-VASc is the standard score for estimating stroke risk in non-valvular atrial fibrillation and framing the anticoagulation discussion. Each risk factor adds one point — two for age 75 or older and two for a prior stroke, TIA, or thromboembolism. Tick the factors that apply and select the age band for the total score and the annual stroke-risk estimate published with the score.
Calculate the score
The score, item by item
| Letter | Risk factor | Points |
|---|---|---|
| C | Congestive heart failure / left ventricular dysfunction | 1 |
| H | Hypertension | 1 |
| A₂ | Age 75 or older | 2 |
| D | Diabetes mellitus | 1 |
| S₂ | Prior stroke, TIA, or thromboembolism | 2 |
| V | Vascular disease (prior MI, peripheral artery disease, aortic plaque) | 1 |
| A | Age 65–74 | 1 |
| Sc | Sex category — female | 1 |
Published annual stroke risk by score (Lip et al.)
| Score | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
|---|---|---|---|---|---|---|---|---|---|---|
| Stroke risk / year | 0% | 1.3% | 2.2% | 3.2% | 4.0% | 6.7% | 9.8% | 9.6% | 6.7% | 15.2% |
These percentages are the widely published estimates from the cohort used to validate the score (Lip et al.); later studies in contemporary, often anticoagulated, populations report lower event rates at several scores, so treat the figures as the score's reference frame rather than a prediction for an individual patient. Note also that the female-sex point behaves as a risk modifier: guidelines interpret the threshold differently by sex — anticoagulation is generally considered at scores of 2 or more in men and 3 or more in women — and a score built only from the sex point is not treated as an indication on its own. For cardiology practices, a correctly documented score is also an audit point: the risk factors behind it must match the problem list, which is one of the checks in our cardiology billing reviews.
Disclaimer: This calculator is educational only and is not medical advice. It does not replace clinical judgment, a bleeding-risk assessment, or current ACC/AHA/HRS and ESC guidance. Anticoagulation decisions belong to the treating clinician and patient together.
Frequently asked questions
What score means anticoagulation should be considered?
As general information from current guidelines: oral anticoagulation is generally considered at a CHA2DS2-VASc score of 2 or more in men and 3 or more in women, and recommended at higher scores, always weighed against bleeding risk and patient preference. A score of 0 (men) or 1 (women, the sex point alone) is generally managed without anticoagulation.
Does the score apply to every atrial fibrillation patient?
CHA2DS2-VASc was developed for non-valvular atrial fibrillation. Patients with mechanical heart valves or moderate-to-severe mitral stenosis are anticoagulated on the basis of the valve disease itself, not this score. It also estimates risk in patients not yet anticoagulated; it is not used to judge whether existing therapy is "working."
Why do the published stroke rates not rise evenly with the score?
The percentages come from the validation cohort published by Lip et al., in which the highest scores had small patient numbers — that is why the estimates at scores 7 and 8 sit below the trend. Contemporary cohorts generally show lower absolute rates. The score's ranking of patients is more reliable than any single percentage.