Risk factors
CHA2DS2-VASc explained in plain language: each letter is one risk factor worth 1 or 2 points. Age contributes cha2ds2 vasc age points in two bands — 65–74 (+1) or 75 and older (+2) — tick only one.
A handy cha2ds2 vasc mnemonic: C-H-A2-D-S2-V-A-Sc — the "2"s remind you that age 75+ and prior stroke count double.
Your score
Breakdown
- Tick a risk factor above to see the breakdown.
Adjusted annual stroke rate (cohort reference): 0%
A score of 1 based only on female sex is generally treated like a score of 0 per guidelines — female sex alone is a risk modifier, not an indication for anticoagulation.
Annual rates are adjusted stroke rates from a large published AFib cohort (Friberg et al., European Heart Journal, 2012). They describe that population — individual risk varies widely and these figures are not a personal prediction.
Interpretation table
This cha2ds2 vasc chart summarises every score. Scores run from a cha2ds2 vasc score 0 (lowest) to 9 (highest).
The cha2ds2 vasc anticoagulation threshold in guidelines sits between scores 1 and 2: 0 → anticoagulation generally not indicated, 1 → consider, 2 or more → generally recommended. For example, a cha2ds2 vasc score 2 carries an adjusted annual stroke rate of about 2.2%, and a cha2ds2 vasc score 5 about 6.7%.
| Score | Category | Annual stroke rate* | Guideline context (general, per ESC/AHA) |
|---|---|---|---|
| 0 | Low risk | 0% | OAC generally not indicated |
| 1 | Consider | 1.3% | OAC should be considered; individualise. Female-only 1 ≈ treated as 0 |
| 2 | High risk | 2.2% | OAC generally recommended |
| 3 | High risk | 3.2% | OAC generally recommended |
| 4 | High risk | 4.0% | OAC generally recommended |
| 5 | High risk | 6.7% | OAC generally recommended |
| 6 | High risk | 9.8% | OAC generally recommended |
| 7 | High risk | 9.6% | OAC generally recommended |
| 8 | High risk | 6.7% | OAC generally recommended |
| 9 | High risk | 15.2% | OAC generally recommended |
* Adjusted annual stroke rates from Friberg et al., Eur Heart J 2012 (Swedish AFib cohort), as referenced by major clinical calculators. Cohort estimates for education — not individual predictions. OAC = oral anticoagulation. Final therapy decisions always rest with a clinician, who also weighs bleeding risk.
Worked examples
Scope boundary — what this tool does not do
- It does not diagnose atrial fibrillation or any condition.
- It does not assess bleeding risk — it does not include the HAS-BLED score, which clinicians weigh alongside CHA2DS2-VASc.
- It does not recommend, dose, or choose any medication for any individual.
- Scores change as risk factors change (for example, crossing an age band) — reassessment is a clinical task.
- Looking for an afib stroke prevention calculator? Prevention choices — lifestyle measures or anticoagulation — are clinical decisions made with a doctor; this tool only estimates the risk score.
Frequently asked questions
What is the CHA2DS2-VASc score?
CHA2DS2-VASc is a clinical risk score used to estimate the risk of stroke in people with atrial fibrillation (AFib). It adds points for eight factors — heart failure, hypertension, age, diabetes, prior stroke or TIA, vascular disease, and sex — for a maximum of 9 points. Higher scores correspond to higher observed stroke rates in published cohorts. It is an educational and decision-support aid, not a diagnosis.
What does each letter in CHA2DS2-VASc stand for?
C = congestive heart failure (1 point); H = hypertension (1); A2 = age 75 or older (2); D = diabetes mellitus (1); S2 = prior stroke, TIA, or thromboembolism (2); V = vascular disease such as prior heart attack, peripheral artery disease, or aortic plaque (1); A = age 65-74 (1); Sc = sex category, female (1). The cha2ds2 vasc congestive heart failure item covers diagnosed heart failure or left-ventricular dysfunction. The cha2ds2 vasc diabetes item and the cha2ds2 vasc female item each add one point.
How is the CHA2DS2-VASc score calculated?
Here is how to calculate cha2ds2 vasc by hand: add the points for each factor that applies. For example, a 70-year-old man with hypertension and diabetes scores 1 (hypertension) + 1 (diabetes) + 1 (age 65-74) = 3. The two age bands are mutually exclusive: age 75 or older scores 2 points, not 3. This page's calculator adds the points automatically as you tick the boxes.
What CHA2DS2-VASc score means blood thinners are needed?
As general guideline context (per ESC/AHA guidelines): a score of 0 generally means no anticoagulation is indicated; a score of 1 means anticoagulation should be considered; a score of 2 or more means anticoagulation is generally recommended. These are population-level guidelines, not personal advice — only a clinician who knows the full clinical picture, including bleeding risk, can decide on therapy.
What does a CHA2DS2-VASc score of 0 mean?
A score of 0 indicates the lowest observed stroke risk in published AFib cohorts (adjusted annual stroke rate near 0%). Per ESC/AHA guidelines, anticoagulation is generally not indicated at a score of 0. Managing underlying conditions still matters, and the score should be rechecked over time as risk factors change.
A woman scores 1 only because she is female — what does that mean?
Guidelines treat a score of 1 based solely on the female sex category like a score of 0: female sex alone is a risk modifier, not an indication to start anticoagulation. This calculator flags that situation explicitly. Once any additional point is present (score 2 or more in women), anticoagulation is generally recommended per guidelines.
How accurate is the stroke-risk estimate?
The annual rates shown (for example, about 2.2% at a score of 2 and about 6.7% at a score of 5) come from a large published Swedish AFib cohort (Friberg et al., European Heart Journal, 2012). They describe what happened in that population — individual risk varies widely, and the original studies did not include every modern treatment. Treat the numbers as educational context, not a personal prediction.
What counts as vascular disease in CHA2DS2-VASc?
Vascular disease generally means prior myocardial infarction (heart attack), peripheral artery disease, or complex aortic plaque. If you are unsure whether a condition qualifies, a clinician should confirm — only count a diagnosed condition.
What is the difference between CHADS2 and CHA2DS2-VASc?
CHADS2 is the older, simpler score (heart failure, hypertension, age 75 or older, diabetes, prior stroke or TIA; maximum 6). CHA2DS2-VASc adds vascular disease, the 65-74 age band, and female sex, and gives extra weight to age 75+ and prior stroke. CHA2DS2-VASc identifies truly low-risk patients better and is the score recommended by current ESC/AHA guidelines.
Is this calculator medical advice?
No. This is an educational tool. It does not diagnose atrial fibrillation, does not assess bleeding risk (for example, it does not include the HAS-BLED score), and does not recommend treatment for any individual. Anticoagulation decisions require a clinician's judgment. If you have AFib or symptoms such as palpitations, see a doctor.
Free tool by NRTechStudio