CHA₂DS₂-VASc scores stroke risk in atrial fibrillation from 0 to 9: 1 point each for heart failure, hypertension, diabetes, vascular disease, age 65–74 and female sex, and 2 points each for age 75 or older and prior stroke or TIA. US guidelines recommend anticoagulation at 2 or more in men and 3 or more in women. The 2024 ESC guideline uses CHA₂DS₂-VA, which drops the sex point, with a threshold of 2.
This calculator gives both scores, the stroke and thromboembolism rates seen in untreated patients at each score in two published cohorts, and the matching US and European recommendation band. It is written for clinicians and students.
How to use this calculator
- Enter the patient's age. The calculator adds 1 point for 65–74 or 2 for 75 and older.
- Choose sex. Female adds 1 point to CHA₂DS₂-VASc but nothing to CHA₂DS₂-VA.
- Tick each risk factor in the history, including past events and treated conditions.
- Read both scores, the annual event rates and the guideline band.
CHA₂DS₂-VASc points table
| Letter | Risk factor | Points |
|---|---|---|
| C | Congestive heart failure or LV dysfunction | 1 |
| H | Hypertension (or on treatment for it) | 1 |
| A₂ | Age 75 years or older | 2 |
| D | Diabetes mellitus | 1 |
| S₂ | Prior stroke, TIA or thromboembolism | 2 |
| V | Vascular disease (prior MI, peripheral artery disease or aortic plaque) | 1 |
| A | Age 65–74 years | 1 |
| Sc | Sex category: female (not in CHA₂DS₂-VA) | 1 |
Lip and colleagues (2010) built the score by refining the 2006 Birmingham/NICE schema and tested it on 1,084 patients from the Euro Heart Survey for AF. Those it labelled low risk had no thromboembolic events, while 1.4% of patients labelled low risk by CHADS₂ did. The two age bands are mutually exclusive: a patient gets 1 or 2 age points, never 3.
Stroke risk at each score
Annual event rates in patients not on anticoagulation, from the original Euro Heart Survey and the large Danish validation cohort.
| CHA₂DS₂-VASc | Adjusted stroke rate, Lip 2010 (%/year) | Thromboembolism at 1 year, Olesen 2011 (per 100 person-years) |
|---|---|---|
| 0 | 0.0 | 0.78 |
| 1 | 1.3 | 2.01 |
| 2 | 2.2 | 3.71 |
| 3 | 3.2 | 5.92 |
| 4 | 4.0 | 9.27 |
| 5 | 6.7 | 15.26 |
| 6 | 9.8 | 19.74 |
| 7 | 9.6 | 21.5 |
| 8 | 6.7 | 22.38 |
| 9 | 15.2 | 23.64 |
The two columns differ because the cohorts differ. Olesen and colleagues followed 73,538 Danish hospital patients with non-valvular AF who were not treated with a vitamin K antagonist or heparin; their endpoint included hospital admission and death from peripheral embolism, ischaemic stroke and pulmonary embolism. Lip's cohort was smaller, so the rates at 7 to 9 rest on few patients and do not rise smoothly. Over 10 years the Danish rates were lower, falling to 0.66 per 100 person-years at 0 and 15.89 at 9, as the sickest patients died early.
What the guidelines recommend
| Score | ACC/AHA/ACCP/HRS 2023 (CHA₂DS₂-VASc) | ESC 2024 (CHA₂DS₂-VA) |
|---|---|---|
| 0 (men) / 1 (women); VA 0 | Low risk: no recommendation to anticoagulate on the score alone | CHA₂DS₂-VA 0: no score-based indication (ESC 2024) |
| 1 (men) / 2 (women); VA 1 | Annual risk 1% to <2%: anticoagulation reasonable (ACC/AHA 2023, class 2a) | CHA₂DS₂-VA 1: oral anticoagulation should be considered (ESC 2024) |
| ≥2 (men) / ≥3 (women); VA ≥2 | Annual risk ≥2%: anticoagulation recommended (ACC/AHA 2023, class 1) | CHA₂DS₂-VA ≥2: oral anticoagulation recommended (ESC 2024) |
The US guideline frames its advice around estimated annual thromboembolic risk (≥2% a year, or 1% to under 2%) and says any validated score can be used, naming CHA₂DS₂-VASc, ATRIA and GARFIELD-AF. It recommends direct oral anticoagulants over warfarin for eligible patients without moderate to severe rheumatic mitral stenosis or a mechanical valve, and says aspirin, alone or with clopidogrel, should not be used instead of anticoagulation. For intermediate-risk patients who are unsure, it suggests looking at other risk modifiers or scores to support a shared decision.
Worked examples
Six sample patients scored with the calculator's own functions.
| Patient | CHA₂DS₂-VASc | CHA₂DS₂-VA | ACC/AHA 2023 band | ESC 2024 band |
|---|---|---|---|---|
| Man, 58, no other risk factors | 0 | 0 | low | low |
| Woman, 60, no other risk factors | 1 | 0 | low | low |
| Man, 68, hypertension | 2 | 2 | high | high |
| Woman, 72, hypertension | 3 | 2 | high | high |
| Man, 79, diabetes and prior MI | 4 | 4 | high | high |
| Woman, 81, prior stroke and heart failure | 6 | 5 | high | high |
The 60-year-old woman scores 1 on CHA₂DS₂-VASc but 0 on CHA₂DS₂-VA, and both guidelines place her in the low band. The 72-year-old woman with hypertension scores 3: the US guideline counts that as high risk, and ESC reaches the same answer with a VA of 2.
Why the sex point is changing
In the Danish data, women whose only point was sex had a 1-year rate of 1.24 per 100 person-years, close to the 0.78 at score 0, while age 65–74 alone gave 2.88. The ESC task force concluded that female sex is an age-dependent risk modifier rather than a risk factor in itself, that including it complicates practice, and that it leaves out people who are non-binary, transgender or on sex hormone therapy. Its CHA₂DS₂-VA therefore uses one threshold for everyone. The US guideline kept CHA₂DS₂-VASc but sets the women's thresholds one point higher, which gives the same answer in most patients.
Common mistakes
- Giving 3 age points. Age 65–74 scores 1 and 75 or older scores 2; they never add together.
- Missing past events. A TIA or stroke years ago still scores 2 points, and treated hypertension or diabetes still counts.
- Using the same threshold for women. With CHA₂DS₂-VASc, a woman needs 3 points for the high band; with CHA₂DS₂-VA, the sex point is not counted at all.
- Using it in valvular AF. Mechanical valves and moderate to severe rheumatic mitral stenosis are managed separately.
- Ignoring bleeding risk. Stroke risk is only half the decision; guidelines ask for a separate bleeding assessment.
More clinical tools: QTc calculator, ankle brachial pressure index, FIB-4 liver fibrosis index, Centor score and A1C to average glucose.
For healthcare professionals and students only. CHA₂DS₂-VASc and CHA₂DS₂-VA estimate stroke risk in atrial fibrillation; they do not decide treatment, and this tool offers no medical advice or drug dosing. Anyone with sudden facial droop, arm weakness or speech problems should call emergency services. Patients should discuss anticoagulation with their own clinician.
Frequently asked questions
What is the CHA₂DS₂-VASc score?
A stroke risk score for people with atrial fibrillation (AF). Each letter is a risk factor: Congestive heart failure (1), Hypertension (1), Age 75 or older (2), Diabetes (1), prior Stroke, TIA or thromboembolism (2), Vascular disease (1), Age 65–74 (1) and Sex category, female (1). It runs from 0 to 9. Lip and colleagues published it in Chest in 2010.
What is a high CHA₂DS₂-VASc score?
The 2023 ACC/AHA/ACCP/HRS guideline treats an annual thromboembolic risk of 2% or more as the point where anticoagulation is recommended, and gives a CHA₂DS₂-VASc of 2 or more in men and 3 or more in women as the example. A score of 1 in men or 2 in women is intermediate (1% to under 2% a year), where anticoagulation is reasonable.
Why do women need a higher score?
Female sex adds 1 point, but on its own it does not raise risk much. In the Danish registry study by Olesen and colleagues, women whose only point was sex had a 1-year thromboembolism rate of 1.24 per 100 person-years, against 0.78 at a score of 0. That is why US thresholds are one point higher for women, and why the 2024 ESC guideline dropped the sex point altogether.
What is CHA₂DS₂-VA?
The 2024 European Society of Cardiology version of the score. It is CHA₂DS₂-VASc without the sex category, so it runs from 0 to 8. The ESC says female sex is an age-dependent risk modifier rather than a risk factor itself, and that leaving it out also covers people who are non-binary, transgender or on sex hormone therapy. ESC recommends oral anticoagulation at a CHA₂DS₂-VA of 2 or more and says it should be considered at 1.
What does a CHA₂DS₂-VASc score of 0 mean?
It means no listed risk factor in a man (or a sex-only point in a woman). Untreated patients at 0 had 0.78 thromboembolic events per 100 person-years in the first year in Olesen 2011, and none in Lip's 2010 cohort. The 2023 ACC/AHA guideline says aspirin alone gives no benefit for stroke prevention in AF without risk factors.
What does a score of 2 mean?
For a man, 2 points puts annual risk at about 2% or more, where the ACC/AHA recommends anticoagulation. Lip 2010 found an adjusted stroke rate of 2.2% a year at 2; Olesen 2011 found 3.71 events per 100 person-years at 1 year. For a woman, 2 points is the intermediate band.
Which vascular diseases count for the V point?
Prior myocardial infarction, peripheral artery disease and complex aortic plaque, as defined by Lip 2010. The 2024 ESC definition of vascular disease also includes coronary artery disease.
Does hypertension count if it is well controlled?
Yes. The point is for a history of hypertension or current treatment for it, not for today's blood pressure. The 2024 ESC table defines it as resting blood pressure above 140/90 mmHg on at least two occasions or current antihypertensive treatment.
Is CHA₂DS₂-VASc the same as CHADS₂?
No. CHADS₂ (0–6) counted heart failure, hypertension, age 75 or over, diabetes and 2 points for prior stroke. CHA₂DS₂-VASc adds vascular disease, age 65–74, female sex and 2 points for age 75 or over. Olesen 2012 showed it splits patients with a CHADS₂ of 0–1 into clearly different risk groups.
Does the score decide whether to anticoagulate?
Not on its own. Guidelines use it to estimate stroke risk, then weigh bleeding risk, reversible bleeding factors and the patient's wishes. The ACC/AHA guideline also asks clinicians to assess bleeding risk separately.
Does the score apply to atrial flutter?
Yes. The 2023 ACC/AHA guideline (section 6.8.6) recommends anticoagulation for atrial flutter according to the same risk profile used for AF, and continued anticoagulation after flutter ablation based on thromboembolic risk, because AF often follows.
Does the score apply to people with a mechanical valve or rheumatic mitral stenosis?
No. These patients need anticoagulation regardless of score, and the 2023 ACC/AHA guideline handles them separately. CHA₂DS₂-VASc was developed for non-valvular AF.
Sources & method
- Lip et al. (2010), Chest — Refining clinical risk stratification for predicting stroke and thromboembolism in AF (Euro Heart Survey): the CHA₂DS₂-VASc score
- Olesen et al. (2011), BMJ — Validation of risk stratification schemes for predicting stroke and thromboembolism in AF: nationwide cohort study
- Joglar et al. (2024), Circulation — 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation
- Van Gelder et al. (2024), Eur Heart J — 2024 ESC Guidelines for the management of atrial fibrillation (CHA₂DS₂-VA)
- Magalhães et al. (2016), Arq Bras Cardiol — Executive summary of the II Brazilian Guidelines for Atrial Fibrillation (Table 1: CHA₂DS₂-VASc adjusted stroke rate)
- Olesen et al. (2012), Thromb Haemost — The value of CHA₂DS₂-VASc in patients with a CHADS₂ score of 0–1
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