CHA₂DS₂-VASc Score Calculator (Stroke Risk in Atrial Fibrillation)

Background.

The CHA₂DS₂-VASc score stratifies the risk of stroke and systemic thromboembolism in a patient with non-valvular atrial fibrillation. It is a clinical decision aid for clinicians. It is not a diagnosis, it is not a treatment recommendation, and it says nothing about bleeding risk — that is a separate assessment, and a high bleeding score is not on its own a reason to withhold anticoagulation.

Seven components carry a weight. Congestive heart failure or left-ventricular dysfunction, hypertension, diabetes, vascular disease and the female sex category each score one point. Prior stroke, TIA or systemic thromboembolism scores two. Age is worth two points at 75 and over and one point between 65 and 74. This calculator takes age as a number rather than as two tick boxes, because entering it twice is the single most common way a CHA₂DS₂-VASc score is inflated by a point. The maximum is 9.

The score's authorship is often misattributed. CHADS₂ — congestive heart failure, hypertension, age, diabetes, and doubled stroke — is Gage and colleagues, published in JAMA in 2001. CHA₂DS₂-VASc is Lip and colleagues, published in Chest in 2010, and it refines CHADS₂ by adding vascular disease, an age band at 65 to 74, and the sex category, specifically so that patients CHADS₂ called intermediate could be separated into genuinely low risk and genuinely not.

Since 2024 the two largest guideline bodies no longer agree on what the score contains. The 2020 European Society of Cardiology guideline and the 2023 ACC/AHA/ACCP/HRS guideline both use CHA₂DS₂-VASc with the female sex point and with sex-specific thresholds. The 2024 ESC guideline removes the sex category entirely, names the result CHA₂DS₂-VA, and applies one sexless set of bands: 0 is low risk, 1 is moderate, and 2 or more is high. The stated reasoning is that the incremental risk attributable to female sex has fallen to non-significance in recent cohorts. This page implements both, defaults to CHA₂DS₂-VASc because it is still what most local protocols specify, and shows you the sex points as a separate output so a one-point difference between the variants is visible rather than mysterious.

The bands themselves differ by variant. Under CHA₂DS₂-VASc as framed by the 2020 ESC guideline, a man scoring 0 and a woman scoring 1 are low risk — a woman always carries the sex point, so 1 is her floor and it represents no clinical risk factor at all. A man scoring 1 and a woman scoring 2 sit in the intermediate band where guidelines say anticoagulation should be considered, and a man scoring 2 or more or a woman scoring 3 or more sits in the band where it is recommended. Under CHA₂DS₂-VA the same three bands apply to everyone at 0, 1 and 2 or more.

This calculator deliberately does not output an annual stroke percentage. Published event rates for a given CHA₂DS₂-VASc score differ by close to an order of magnitude between the Euro Heart Survey, the Swedish atrial fibrillation cohort and the Danish registries, because the cohorts differ in how many patients were anticoagulated and in how events were ascertained. No single per-score rate could be sourced that would be honest across settings, so none is shown. A number invented for the sake of having one would be worse than its absence, and this page says so where you read the answer rather than in a footnote.

Scope matters as much as arithmetic. The score was derived and validated in non-valvular atrial fibrillation. It does not apply to a patient with moderate or severe mitral stenosis or a mechanical heart valve, in whom anticoagulation is indicated regardless of any score. It stratifies risk at a moment in time and needs revisiting as a patient ages or accumulates comorbidity; a score taken at 63 is not the score at 66. And it is one input to a shared decision with a patient, alongside bleeding risk, adherence, renal function and preference — not a substitute for that conversation.

What is cha₂ds₂-vasc score calculator?

CHA₂DS₂-VASc is a risk-factor-based scoring system that estimates the risk of ischaemic stroke and systemic thromboembolism in atrial fibrillation. The acronym expands to congestive heart failure, hypertension, age 75 or over (doubled), diabetes, prior stroke or TIA or thromboembolism (doubled), vascular disease, age 65 to 74, and sex category.

It was introduced by Lip and colleagues in 2010 using the Euro Heart Survey on Atrial Fibrillation cohort of 1,084 patients, as a refinement of the earlier CHADS₂ score. Its practical advantage over CHADS₂ is at the bottom of the range: CHADS₂ placed the majority of patients into an intermediate category, whereas CHA₂DS₂-VASc identifies a genuinely low-risk group in whom antithrombotic therapy is not indicated.

CHA₂DS₂-VA is the same score with the sex category removed, introduced by the 2024 ESC atrial fibrillation guideline. Its maximum is 8 rather than 9, and its bands are sexless. For a male patient the two scores are numerically identical; for a female patient CHA₂DS₂-VA is always exactly one point lower.

What neither score is: a bleeding assessment, a drug choice, a dosing tool, or a statement about a specific person's probability of stroke this year. It is a stratification instrument that places a patient in a band, and the band frames a conversation.

How to use this calculator.

1. 01Choose the variant your protocol uses. CHA₂DS₂-VASc counts the female sex category and uses sex-specific bands; CHA₂DS₂-VA, from the 2024 ESC guideline, does not count sex and uses one set of bands for everyone.
2. 02Enter the patient's age as a number. The calculator assigns 2 points at 75 and over and 1 point from 65 to 74 — you do not tick an age box, which is how age gets double-counted.
3. 03Select the sex category. It changes the score only on the VASc variant, but it changes the band on that variant for every patient.
4. 04Answer the five comorbidity items from documented history. Vascular disease means prior myocardial infarction, peripheral artery disease or aortic plaque — not hypertension, which is scored separately.
5. 05Read the age points and sex points alongside the total so you can see exactly what produced it.
6. 06Assess bleeding risk separately before any anticoagulation decision, and remember that a high bleeding score is a prompt to address modifiable bleeding factors, not to withhold anticoagulation.
7. 07Confirm the patient has non-valvular atrial fibrillation. With moderate or severe mitral stenosis or a mechanical valve, the score does not apply.
8. 08Rescore when the patient crosses an age band or acquires a new risk factor — this is not a once-in-a-lifetime number.

The formula.

CHA₂DS₂-VASc is a simple weighted sum. Congestive heart failure or left-ventricular dysfunction adds 1. Hypertension adds 1. Age 75 or over adds 2. Diabetes mellitus adds 1. Prior stroke, TIA or systemic thromboembolism adds 2. Vascular disease — prior MI, peripheral artery disease or aortic plaque — adds 1. Age 65 to 74 adds 1. Female sex category adds 1. The maximum is 9.

The two age terms are mutually exclusive. Because age is entered here as a number rather than as two independent checkboxes, the calculator evaluates 75-and-over first and 65-to-74 only if that fails, so a 78-year-old scores 2 age points and never 3. The age output is shown separately for exactly this reason.

Rounding stage: there is none. Every weight is an integer and the total is an exact integer sum. The age comparison uses the value as entered, so 74.9 years scores 1 age point and 75.0 scores 2 — the literal reading of "age 75 years or over". No intermediate value is rounded and no threshold is approached from a floating-point artefact.

CHA₂DS₂-VA, from the 2024 ESC guideline, is the identical sum with the sex term deleted, giving a maximum of 8. For a male patient the two totals are always equal. For a female patient CHA₂DS₂-VA is always exactly one lower — which is the whole point of the change, and why the sex points are exposed as their own output.

Banding differs by variant. On CHA₂DS₂-VASc, following the 2020 ESC guideline's framing: men are low risk at 0, intermediate at 1, and high at 2 or more; women are low risk at 1 — the sex point alone, meaning no clinical risk factor — intermediate at 2, and high at 3 or more. On CHA₂DS₂-VA, everyone is low risk at 0, moderate at 1, and high at 2 or more.

Worked through the example on this page: hypertension 1, age 78 giving 2, diabetes 1, and female sex 1 sum to 1 + 2 + 1 + 1 = 5. Five is 3 or more for a woman, so the CHA₂DS₂-VASc band is high risk. Removing the sex point gives a CHA₂DS₂-VA total of 4, which is 2 or more, so that band is high risk as well. The variants diverge for low scorers, not this one: a 60-year-old woman with no risk factors scores 1 on VASc and 0 on VA.

A worked example.

Frequently asked questions.

References& sources.

1. [1]Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJGM. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the Euro Heart Survey on Atrial Fibrillation. Chest. 2010;137(2):263–272. Derivation of the CHA₂DS₂-VASc acronym, n = 1,084. (Abstract retrieved verbatim 2026-07-29; publisher full text paywalled.)
2. [2]Gage BF, Waterman AD, Shannon W, et al. Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation. JAMA. 2001;285(22):2864–2870. The CHADS₂ score that CHA₂DS₂-VASc refines — cited to correct the common misattribution of CHA₂DS₂-VASc to Gage. (Consulted 2026-07-29.)
3. [3]Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation. Circulation. 2024;149(1):e1–e156. Source of the component point values and of the vascular-disease definition (prior MI, peripheral artery disease, or aortic plaque). (ahajournals.org blocks automated retrieval; guideline text consulted 2026-07-29 and cross-checked against the Europace reference below.)
4. [4]Hindricks G, Potpara T, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2021;42(5):373–498. Source of the sex-specific bands used on this page: low risk at 0 in men and 1 in women; anticoagulation to be considered at 1 in men and 2 in women; recommended at 2 or more in men and 3 or more in women. (Retrieved 2026-07-29.)
5. [5]Van Gelder IC, Rienstra M, Bunting KV, et al. 2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2024;45(36):3314–3414. Introduces CHA₂DS₂-VA with the sex category removed and the sexless bands 0 low, 1 moderate, 2 or more high. (Retrieved 2026-07-29.)
6. [6]Lip GYH, et al. Refining the CHA₂DS₂-VASc risk stratification scheme: shall we drop the sex category criterion? EP Europace. 2024;26(11):euae280. Used as the independent cross-check on the component point list, letter by letter, and as the source quoting the 2024 ESC three-band CHA₂DS₂-VA stratification. (Retrieved 2026-07-29.)