The ABI Calculator helps you assess your risk for Peripheral Artery Disease (PAD) by computing your Ankle-Brachial Index. This simple, non-invasive ratio of ankle to arm blood pressure is a crucial indicator of vascular health. Use our tool for a quick evaluation of your lower extremity arterial flow.
Formula:
The Ankle-Brachial Index (ABI) is calculated as the ratio of the highest systolic blood pressure measured at the ankle to the highest systolic blood pressure in the arm (brachial artery).
- Left ABI = Left Ankle SBP / Highest Brachial SBP
- Right ABI = Right Ankle SBP / Highest Brachial SBP
Where:
- Ankle SBP = Systolic Blood Pressure measured at the ankle (dorsalis pedis or posterior tibial artery).
- Brachial SBP = Systolic Blood Pressure measured at the brachial artery (arm).
- Highest Brachial SBP = The higher of the left or right brachial systolic pressures.
A typical normal ABI range is 0.91 to 1.30.