Calculate your CHA2DS2-VASc score to estimate annual stroke risk in atrial fibrillation, with sex-specific risk bands and the 2024 ESC CHA2DS2-VA update.
CHA2DS2-VASc Formula
The CHA2DS2-VASc score adds one or two points for each stroke risk factor present in a person with non-valvular atrial fibrillation, then reads the total against a table of yearly stroke risk:
CHA2DS2-VASc = C + H + A2 + D + S2 + V + A + Sc
The 2024 European Society of Cardiology guideline uses a simplified version, the CHA2DS2-VA score, which is the same sum with the sex point removed:
CHA2DS2-VA = C + H + A2 + D + S2 + V + A
Variables:
- C is congestive heart failure or left ventricular systolic dysfunction (1 point)
- H is hypertension, either treated or with blood pressure consistently above 140/90 mmHg (1 point)
- A2 is age 75 years or older (2 points)
- D is diabetes mellitus (1 point)
- S2 is a prior stroke, transient ischemic attack, or thromboembolism (2 points)
- V is vascular disease, meaning prior myocardial infarction, peripheral artery disease, or aortic plaque (1 point)
- A is age 65 to 74 years (1 point)
- Sc is sex category, scored only when the patient is female (1 point)
Age is counted once. Someone 75 or older takes the 2 points from A2 and nothing from A, so the maximum CHA2DS2-VASc score is 9, not 10, and the maximum CHA2DS2-VA score is 8. Pick the scoring system at the top of the calculator. In classic mode the tool adds the female sex point and applies sex-specific treatment thresholds. In CHA2DS2-VA mode it drops the sex point and applies a single threshold to everyone. When you type an age, the calculator assigns the correct age band for you, so the two age rows can never both be counted. Each risk factor is a simple present or absent choice, and the two-point items (age 75 plus and prior stroke or TIA) are the ones that move the total the most.
Stroke Risk by CHA2DS2-VASc Score
A higher score maps to a higher yearly risk of ischemic stroke or systemic embolism. The percentages below come from the Swedish Atrial Fibrillation cohort of 182,678 patients (Friberg 2012), the source most stroke calculators use for adjusted annual risk.
| CHA2DS2-VASc score | Adjusted stroke risk (% per year) | Risk band |
|---|---|---|
| 0 | 0.2 | Low |
| 1 | 0.6 | Low |
| 2 | 2.2 | Moderate |
| 3 | 3.2 | Moderate |
| 4 | 4.8 | High |
| 5 | 7.2 | High |
| 6 | 9.7 | High |
| 7 | 11.2 | Very high |
| 8 | 10.8 | Very high |
| 9 | 12.2 | Very high |
Guidelines translate the score into a treatment decision. A score of 0 in a man or 1 in a woman (the sex point alone) is low risk, and no oral anticoagulant is advised. A score of 1 in a man or 2 in a woman is the borderline zone where anticoagulation may be considered. A score of 2 or more in a man, or 3 or more in a woman, is the level at which an oral anticoagulant is recommended unless bleeding risk rules it out.
CHA2DS2-VASc Compared With the 2024 ESC CHA2DS2-VA Score
The 2024 ESC atrial fibrillation guideline retired the sex point and moved to the sex-neutral CHA2DS2-VA score. The reasoning is that female sex behaves as an age-dependent risk modifier rather than a standalone risk factor, and that a sex point is awkward for non-binary and transgender patients. This comparison does not appear on most CHA2DS2-VASc pages, so it is worth seeing side by side.
| Feature | CHA2DS2-VASc (classic) | CHA2DS2-VA (2024 ESC) |
|---|---|---|
| Female sex point | Adds 1 point | Not scored |
| Maximum score | 9 | 8 |
| Consider anticoagulation at | 1 (man) or 2 (woman) | 1 (anyone) |
| Recommend anticoagulation at | 2 (man) or 3 (woman) | 2 (anyone) |
| Woman, one clinical risk factor | Score 2, consider | Score 1, consider |
The two systems usually reach the same treatment decision. That is by design: the classic score raised the female thresholds by one point, so removing the sex point and lowering everyone to a single threshold lands most patients in the same band. The CHA2DS2-VA score mainly makes the counting simpler and removes the need to treat sex as a separate tick box.
Example Problems
Example 1: A 72-year-old woman has treated hypertension and diabetes and no other risk factors.
Age 72 falls in the 65 to 74 band, so A adds 1. Hypertension adds 1, diabetes adds 1, and female sex adds 1. The total is CHA2DS2-VASc = 1 + 1 + 1 + 1 = 4, which maps to about 4.8 percent stroke risk per year and sits firmly in the recommend-anticoagulation band. Removing the sex point gives CHA2DS2-VA = 3, which also recommends anticoagulation, so the decision is the same either way.
Example 2: A 60-year-old man has no listed risk factors.
Age 60 is under 65, so it adds nothing, and with no other factors the CHA2DS2-VASc score is 0. That is low risk, about 0.2 percent per year, and no anticoagulant is advised. If the same man were 66, age would add 1 point, moving him to a score of 1 and into the zone where anticoagulation may be considered.
Frequently Asked Questions
What CHA2DS2-VASc score means you need blood thinners?
An oral anticoagulant is generally recommended at a score of 2 or higher in men and 3 or higher in women. A score of 1 in a man or 2 in a woman is a judgment call where the drug may be offered after weighing bleeding risk and personal preference. A score of 0 in a man, or 1 in a woman from the sex point alone, is low enough that anticoagulation is not advised. These are guideline thresholds, and the final decision belongs to you and your clinician.
Why is the maximum CHA2DS2-VASc score 9 and not 10?
The letters seem to add up to 10 points, but age is only counted once. Being 75 or older scores 2 points and cancels the separate 1 point for age 65 to 74, so the two age rows can never both apply. That caps the classic score at 9 and the sex-neutral CHA2DS2-VA score at 8.
Is the CHA2DS2-VASc score being replaced?
The 2024 ESC guideline now prefers the CHA2DS2-VA score, which drops the female sex point, while much of clinical practice and many electronic records still use the classic CHA2DS2-VASc. Both rest on the same risk factors and usually point to the same treatment, so knowing your score in either system is useful. The calculator shows both totals at once so you can compare them for the same inputs.