Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
CHA2DS2-VASc score
3
Approx. annual stroke risk (%)
3.2
General guidance
Anticoagulation generally recommended
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How to use this
- 1Enter congestive heart failure / lv dysfunction.
- 2Enter hypertension.
- 3Enter age (years).
- 4Enter diabetes mellitus.
- 5Enter prior stroke, tia, or thromboembolism.
- 6Enter vascular disease (mi, pad, aortic plaque).
- 7Enter sex.
- 8Read your cha2ds2-vasc score on the right — it updates as you type.
- 9Hit Share to keep the scenario or send it to someone.
About this calculator
CHA2DS2-VASc estimates annual ischemic stroke risk in patients with nonvalvular atrial fibrillation and is the standard tool used to decide whether anticoagulation is warranted. Points are assigned for Congestive heart failure (1), Hypertension (1), Age 75+ (2), Diabetes (1), prior Stroke/TIA/thromboembolism (2), Vascular disease — prior MI, peripheral arterial disease, or aortic plaque (1), Age 65-74 (1), and Sex category female (1). Most guidelines recommend anticoagulation for a score of 2 or more in men or 3 or more in women (since the sex point alone in an otherwise low-risk woman is not considered sufficient justification alone), with a score of 0 in men or 1 in women (from sex alone) generally not requiring anticoagulation. This score does not replace assessment of bleeding risk (paired tools like HAS-BLED exist for that) or account for AF burden, valve disease, or renal function, all of which factor into the final anticoagulation decision alongside patient preference. This tool is for education and workflow support only — not medical advice. Always verify results with a clinician and use clinical judgment alongside your institution's protocols.
Worked example
Using the values the calculator loads with:
Inputs
- Congestive heart failure / LV dysfunction: No
- Hypertension: Yes (+1)
- Age: 70 years
- Diabetes mellitus: No
- Prior stroke, TIA, or thromboembolism: No
- Vascular disease (MI, PAD, aortic plaque): No
- Sex: Female (+1)
Results
- CHA2DS2-VASc score: 3
- Approx. annual stroke risk (%): 3.2
- General guidance: Anticoagulation generally recommended
What each field means
Inputs
- Congestive heart failure / LV dysfunction
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Hypertension
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Age (years)
- The age used in the calculation, measured in years. Starts at 70 years so you have a working example on load. Accepted range: 18–110 years.
- Diabetes mellitus
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Prior stroke, TIA, or thromboembolism
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+2), No.
- Vascular disease (MI, PAD, aortic plaque)
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Sex
- Pick the option that matches your situation — the maths changes per option. Choices: Male, Female (+1).
Results
- CHA2DS2-VASc score
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Approx. annual stroke risk (%)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- General guidance
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why does female sex only add a point sometimes?
Current guidelines treat female sex as a risk modifier rather than an independent risk factor — a woman with no other risk factors (score of 0 otherwise) is not considered to need anticoagulation based on the sex point alone. The sex point becomes relevant when combined with at least one other risk factor.
What score threshold triggers anticoagulation?
Most guidelines recommend anticoagulation at a score of 2 or higher in men and 3 or higher in women, reflecting that the sex-alone score of 1 in women is treated similarly to a score of 0 in men. Scores of 1 in men are a gray zone where anticoagulation may be considered based on shared decision-making.
Does this score account for bleeding risk?
No — CHA2DS2-VASc estimates stroke risk only. Bleeding risk is assessed separately, commonly with the HAS-BLED score, and the anticoagulation decision weighs both stroke risk and bleeding risk together along with patient preference and practical factors like fall risk and medication adherence.
Is this valid for valvular atrial fibrillation?
No. CHA2DS2-VASc was derived for nonvalvular atrial fibrillation. Patients with moderate-to-severe mitral stenosis or mechanical heart valves have a different, generally higher, baseline stroke risk and different anticoagulation requirements (often mandatory warfarin, not DOACs) regardless of their CHA2DS2-VASc score.
Accuracy and limitations
- Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
- Results do not account for medical conditions, medication, or pregnancy.
- Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it.
Related tools
HAS-BLED Bleeding Risk Calculator
Estimate major bleeding risk on anticoagulation for atrial fibrillation.
Shock Index Calculator
Screen for occult hemodynamic compromise from heart rate and systolic BP.
QTc Calculator (Bazett & Fridericia)
Correct the QT interval for heart rate using two standard formulas.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). CHA2DS2-VASc Score Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/cha2ds2-vasc-score
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/cha2ds2-vasc-score" target="_blank" rel="noopener">CHA2DS2-VASc Score Calculator — RevenueLab</a> (2026).</p>
Source: [CHA2DS2-VASc Score Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/cha2ds2-vasc-score) (2026).