Abi Calculator
Calculate the Ankle-Brachial Index (ABI) to assess peripheral artery disease risk. Enter systolic blood pressures from both arms and ankles.
Published by:
isCalculator Editorial Team
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How to Use the ABI Calculator
This calculator computes the Ankle-Brachial Index (ABI) to screen for peripheral artery disease (PAD). All values must be in mmHg (millimeters of mercury).
- Enter systolic pressures for both arms and both ankles in the provided fields. Use whole numbers only (e.g., 120).
- Click "Calculate ABI" to process the data. The calculator will validate that all entries are positive numbers.
- Read the result displayed below the button:
- The ABI value (rounded to two decimals) is the lower of the right and left ankle pressures divided by the higher arm pressure.
- The interpretation explains the clinical meaning (e.g., normal, borderline, or PAD severity).
- The formula detail shows both ankle-specific ABIs for transparency.
Note: If any field shows a red error, correct the invalid entry (must be a positive number) and recalculate.
Previous Results
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Frequently Asked Questions
The Ankle-Brachial Index (ABI) is a ratio of blood pressure in the lower legs to that in the arms, used to screen for peripheral artery disease (PAD).
ABI is calculated by dividing the systolic blood pressure at the ankle by the higher of the two arm systolic pressures. The lower of the two ankle pressures is used for the final result.
An ABI below 0.9 indicates peripheral artery disease, while above 1.4 may suggest non-compressible arteries. Consult a healthcare provider for proper diagnosis.
