Ankle Brachial Index Calculator

The Ankle Brachial Index Calculator estimates your ABI score by comparing systolic blood pressure in your ankle to your arm. This tool helps adults assess their cardiovascular health and screen for peripheral artery disease quickly and easily. Whether you are monitoring leg pain, checking for blockages, or tracking heart health risks, this calculator provides clear medical insights to help you take action.

Enter the highest systolic blood pressure reading from the brachial artery (mmHg)
Enter the highest systolic blood pressure reading from the ankle (mmHg)

How Ankle Brachial Index Is Calculated

The Ankle Brachial Index is a simple ratio that compares the blood pressure in your lower legs to the blood pressure in your arms. This calculation helps doctors see if your arteries are blocked or narrowed.

ABI = Ankle Systolic Pressure ÷ Brachial Systolic Pressure

Where:

  • Ankle Pressure: The highest systolic reading from the ankle.
  • Brachial Pressure: The highest systolic reading from the arm.
  1. Record the highest systolic blood pressure from the brachial artery in your arm.
  2. Record the highest systolic blood pressure from the posterior tibial or dorsalis pedis artery in your ankle.
  3. Divide the ankle pressure by the arm pressure to get your ratio.

This method uses the standard ABI formula, which is a trusted, non-invasive way to detect vascular issues and assess cardiovascular risk.

What Your Ankle Brachial Index Means

Your ABI number tells you how well blood is flowing to your legs and helps identify potential narrowing of arteries. Understanding your score allows you to make informed decisions about your health.

Common Ranges

  • Normal (1.0 – 1.4): Blood flow is healthy, suggesting no significant arterial blockage.
  • Borderline (0.91 – 0.99): You might have mild narrowing. Discuss lifestyle changes with your doctor.
  • PAD (0.90 or lower): You likely have peripheral artery disease. Seek medical advice for treatment options.
  • Non-compressible (>1.4): Arteries may be stiff due to calcification. Consult a specialist.

Important: An ABI score below 0.90 is a strong indicator of peripheral artery disease and requires professional evaluation to prevent complications like leg pain or tissue damage.

Disclaimer: This calculator is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician with any questions you may have regarding a medical condition.

If you fall into a borderline or abnormal category, monitor your symptoms closely and schedule a follow-up appointment with a healthcare provider to confirm the results.