🦵 Ankle-Brachial Index (ABI) Calculator

Screen for peripheral artery disease (PAD) by comparing arm/ankle blood pressure

💪 Arm Blood Pressure

Right Arm SBP

Left Arm SBP

🦶 Ankle Blood Pressure

Right Ankle SBP

Left Ankle SBP

📋 Your ABI Results

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Ankle-Brachial Index

ℹ️ How to Use This Calculator & Interpretation Guide ▼

📝 ABI Measurement Instructions

1. Have the patient rest supine for 5-10 minutes before measurement
2. Measure brachial systolic BP in both arms using a Doppler probe
3. Measure systolic BP at both ankles (posterior tibial and dorsalis pedis arteries)
4. Record the highest systolic pressure from each arm and ankle
5. Calculate ABI for each leg by dividing the higher ankle pressure by the higher arm pressure

📈 ABI Interpretation

• 1.0-1.4: Normal (no significant PAD)
• 0.9-0.99: Borderline (mild PAD possible)
0.7-0.89: Moderate PAD (claudication likely)
• ≤0.69: Severe PAD (rest pain/ulceration possible)
• >1.4: Non-compressible vessels (calcification)

🏥 Example Calculation

Patient measurements:

• Right arm: 120 mmHg
• Left arm: 118 mmHg
• Right ankle: 100 mmHg
• Left ankle: 96 mmHg
• ABI: Right = 100/120 = 0.83 (Moderate PAD)
• ABI: Left = 96/120 = 0.80 (Moderate PAD)

⚠️ Important Notes

• ABI is a screening tool, not a diagnostic test
• Results <0.9 or >1.4 should be evaluated by a healthcare professional
• Diabetic patients may have falsely elevated ABI due to arterial calcification
• Always use the higher of the two arm pressures for calculation