CHA2DS2-VASc Score Calculator
Estimate stroke risk in people with non-valvular atrial fibrillation (AF). Fill out the fields below and click calculate.
What is the CHA2DS2-VASc score?
The CHA2DS2-VASc score is a widely used clinical tool to estimate the risk of ischemic stroke in patients with atrial fibrillation. Atrial fibrillation can increase the chance of blood clot formation in the atria, and those clots can travel to the brain and cause stroke. This score helps clinicians decide whether stroke prevention with anticoagulation may be beneficial.
How the acronym breaks down
- C — Congestive heart failure/LV dysfunction: 1 point
- H — Hypertension: 1 point
- A2 — Age 75 years or older: 2 points
- D — Diabetes mellitus: 1 point
- S2 — Prior Stroke/TIA/thromboembolism: 2 points
- V — Vascular disease (MI, PAD, aortic plaque): 1 point
- A — Age 65 to 74 years: 1 point
- Sc — Sex category (female): 1 point
How to use this calculator
To get an accurate result, gather basic clinical information first:
- Current age
- Sex assigned at birth
- History of heart failure, hypertension, diabetes, stroke/TIA, or vascular disease
Enter those values into the calculator above. The tool will return your total CHA2DS2-VASc score, an approximate annual stroke risk, and a simplified interpretation aligned with common guideline patterns.
Approximate annual stroke risk by score
| Score | Estimated Stroke Risk / Year |
|---|---|
| 0 | ~0.2% |
| 1 | ~0.6% |
| 2 | ~2.2% |
| 3 | ~3.2% |
| 4 | ~4.8% |
| 5 | ~7.2% |
| 6 | ~9.7% |
| 7 | ~11.2% |
| 8 | ~10.8% |
| 9 | ~12.2% |
These percentages are population-level estimates and can vary between studies, patient populations, and treatment contexts. They should be interpreted as rough guidance, not exact predictions for an individual patient.
How clinicians interpret the result
General approach in atrial fibrillation
- Lower scores: often low annual stroke risk; anticoagulation may not be necessary.
- Intermediate scores: shared decision-making is important; risks and benefits should be discussed.
- Higher scores: anticoagulation is more often recommended unless bleeding risk is prohibitive.
Importantly, stroke risk scores and bleeding risk are both considered. A clinician may also evaluate kidney function, fall risk, medication interactions, prior bleeding, adherence concerns, and patient preferences before choosing treatment.
Limitations and clinical caveats
- The score is validated for non-valvular AF and is not a one-size-fits-all tool.
- It does not replace individualized assessment by a healthcare professional.
- It does not directly account for all risk modifiers (frailty, biomarkers, echocardiographic findings, etc.).
- Risk estimates may differ by ethnicity, comorbid burden, and treatment setting.
Frequently asked questions
Can this calculator diagnose atrial fibrillation?
No. It only estimates stroke risk after AF is already known or suspected and clinically confirmed.
Does a higher score always mean I should start a blood thinner?
Not always. It means anticoagulation is more likely to provide net benefit, but final decisions require clinical review, including bleeding risk, contraindications, and patient goals.
Should I use this score if I do not have AF?
Generally no. CHA2DS2-VASc is designed for stroke risk stratification in atrial fibrillation. If you are concerned about stroke risk, discuss comprehensive cardiovascular prevention with your clinician.