CHA₂DS₂-VASc Stroke Risk Calculator
Use this calculator to estimate stroke risk in patients with atrial fibrillation and support anticoagulation discussions.
Clinical risk factors
Educational use only. Always confirm decisions with current clinical guidelines and individual patient context.
What is the CHA₂DS₂-VASc score?
The CHA₂DS₂-VASc score (often searched as “CHADS VASc”) is a clinical risk stratification tool used in non-valvular atrial fibrillation (AF) to estimate annual stroke risk. It helps clinicians decide whether anticoagulation therapy is likely to provide more benefit than harm.
This score improved upon the older CHADS2 model by adding additional risk categories, especially age 65–74, vascular disease, and sex category. That allows better identification of patients at low, intermediate, and high risk.
How scoring works
Point allocation
- C – Congestive heart failure/LV dysfunction: 1
- H – Hypertension: 1
- A2 – Age ≥ 75 years: 2
- D – Diabetes mellitus: 1
- S2 – Stroke/TIA/systemic embolism history: 2
- V – Vascular disease: 1
- A – Age 65–74 years: 1
- Sc – Sex category (female): 1
Total possible score: 0 to 9.
How to interpret results
Guideline recommendations vary slightly by region and publication year, but the practical interpretation is generally:
- Men: 0 = low risk; 1 = consider anticoagulation; 2+ = anticoagulation usually recommended.
- Women: 1 (sex point only) = low risk; 2 = consider anticoagulation; 3+ = anticoagulation usually recommended.
Clinical decisions should also include bleeding risk, patient values, kidney function, fall risk, medication interactions, and adherence likelihood.
Why this calculator matters
AF-related stroke can be severe and disabling. The CHA₂DS₂-VASc score gives a structured way to discuss prevention. It turns a broad clinical impression into a reproducible number that can support shared decision-making.
Important limitations
- The score is not a diagnosis tool for atrial fibrillation.
- It does not replace clinician judgment or guideline updates.
- Annual risk percentages are estimates and vary by cohort.
- Bleeding risk must be considered separately (for example, with HAS-BLED).
- Special populations (valvular AF, mechanical valves, pregnancy, severe comorbidity) need individualized assessment.
Quick FAQ
Is “CHADS VASc” the same as “CHA₂DS₂-VASc”?
Yes. “CHADS VASc” is a common shorthand search term, but the full name is CHA₂DS₂-VASc.
Does female sex always require anticoagulation?
No. Female sex alone (with no other risk factors) is generally not treated the same as higher-risk profiles.
Can this tool be used at home by patients?
It can support understanding, but treatment decisions should always be made with a qualified healthcare professional.