CHADS2 Stroke Risk Calculator

Atrial fibrillation stroke risk stratification

Formula

Score = CHF(1) + HTN(1) + Age≥75(1) + DM(1) + Stroke/TIA(2). Range 0-6.

CHADS2 estimates annual stroke risk in non-anticoagulated AF patients. Score ≥2 generally indicates anticoagulation benefit outweighs bleeding risk.

How to Calculate Manually

1
Check each clinical factor that applies
2
Calculator sums the points
3
Shows score, annual stroke risk, and recommendation

Reference Table

Score	Annual Stroke Risk	Adj. Risk (Warfarin)	Recommendation
0	1.9%	0.5%	Aspirin or none
1	2.8%	1.0%	Individualize
2	4.0%	1.5%	Anticoagulate
3	5.9%	2.3%	Anticoagulate
4	8.5%	3.2%	Anticoagulate
5	12.5%	4.7%	Anticoagulate
6	18.2%	7.0%	Anticoagulate

CHADS2 Calculator: Stroke Risk in Atrial Fibrillation

The CHADS2 score is a clinical prediction rule for estimating the annual risk of stroke in patients with non-valvular atrial fibrillation (AF). Developed from the National Registry of Atrial Fibrillation, it helps clinicians decide whether anticoagulation therapy (warfarin or DOACs) is warranted...

Frequently Asked Questions

What does CHADS2 stand for? C=Congestive Heart Failure (1), H=Hypertension (1), A=Age ≥75 (1), D=Diabetes (1), S2=Prior Stroke/TIA (2). Max score = 6.: C=Congestive Heart Failure (1), H=Hypertension (1), A=Age ≥75 (1), D=Diabetes (1), S2=Prior Stroke/TIA (2). Max score = 6.
What do the scores mean? 0=Low risk (1.9%/yr), 1=Moderate (2.8%), 2=Moderate-High (4.0%), 3=High (5.9%), 4=High (8.5%), 5=Very High (12.5%), 6=Very High (18.2%).: 0=Low risk (1.9%/yr), 1=Moderate (2.8%), 2=Moderate-High (4.0%), 3=High (5.9%), 4=High (8.5%), 5=Very High (12.5%), 6=Very High (18.2%).
CHADS2 vs CHA2DS2-VASc? CHA2DS2-VASc adds: Age 65-74 (1), Female (1), Vascular disease (1). More sensitive for low-risk patients. Current guidelines prefer CHA2DS2-VASc.: CHA2DS2-VASc adds: Age 65-74 (1), Female (1), Vascular disease (1). More sensitive for low-risk patients. Current guidelines prefer CHA2DS2-VASc.

Calculator

Formula

Formula

How to Calculate Manually

Reference Table

CHADS2 Calculator: Stroke Risk in Atrial Fibrillation

Frequently Asked Questions

More Health Calculators

Absolute Neutrophil Count (ANC) Calculator

Anion Gap Calculator

Apgar Score Calculator

BMI Calculator

BMR Calculator

Body Fat Percentage Calculator