CHA2DS2-VASc Calculator
Use this tool to estimate stroke risk score in non-valvular atrial fibrillation.
What is the CHA2DS2-VASc score?
The CHA2DS2-VASc score is a validated clinical risk tool used to estimate stroke risk in people with non-valvular atrial fibrillation (AF). If you searched for “chads vasc calcular,” this is the scoring system you are likely trying to calculate.
Clinicians use this score to support decisions about anticoagulation (blood-thinner) therapy. The higher the score, the greater the annual stroke risk, and the more likely anticoagulation may provide net benefit.
How the score is built
Letter-by-letter breakdown
- C: Congestive heart failure / LV dysfunction = 1 point
- H: Hypertension = 1 point
- A2: Age ≥ 75 years = 2 points
- D: Diabetes mellitus = 1 point
- S2: Prior Stroke/TIA/thromboembolism = 2 points
- V: Vascular disease = 1 point
- A: Age 65–74 years = 1 point
- Sc: Sex category (female) = 1 point
Maximum score is 9. Age contributes either 0, 1, or 2 points (never both age categories at the same time).
How to interpret the result
Guidelines differ slightly across regions and are updated over time, but a common practical interpretation is:
- Men: 0 = low risk, 1 = intermediate, ≥2 = anticoagulation usually considered/recommended
- Women: 1 (sex alone) = low risk, 2 = intermediate, ≥3 = anticoagulation usually considered/recommended
Female sex alone is often treated as a risk modifier rather than an isolated indication for anticoagulation. That is why clinical context is essential.
Why this calculator matters
AF-related stroke can be severe and disabling. A structured score helps standardize risk assessment and enables informed conversation between patient and clinician. However, no score captures everything. Bleeding risk, frailty, kidney function, medication access, and patient preferences all matter.
CHADS2 vs CHA2DS2-VASc
CHADS2 is an older score that is simpler but less granular in lower-risk patients. CHA2DS2-VASc adds vascular disease, age 65–74, and sex category to better discriminate stroke risk, especially when CHADS2 looks “low.” In modern practice, CHA2DS2-VASc is generally preferred for non-valvular AF risk stratification.
Common mistakes when calculating
- Double-counting age categories (only one age category can apply).
- Ignoring prior TIA because symptoms resolved.
- Forgetting vascular history such as old MI or PAD.
- Using the score without confirming AF context and valve status.
- Treating calculator output as a diagnosis rather than a decision-support step.
Clinical reminder
This page is an educational replica and not a treatment protocol. If you are making a real-world decision about stroke prevention, review current cardiology guidelines and discuss the case with a qualified healthcare professional.
Quick reference risk table (approximate annual stroke risk)
| CHA2DS2-VASc Score | Estimated Annual Stroke Risk |
|---|---|
| 0 | ~0.0% |
| 1 | ~1.3% |
| 2 | ~2.2% |
| 3 | ~3.2% |
| 4 | ~4.0% |
| 5 | ~6.7% |
| 6 | ~9.8% |
| 7 | ~9.6% |
| 8 | ~6.7% |
| 9 | ~15.2% |