How to Calculate Body Adiposity Index

What is Body Adiposity Index?

The Body Adiposity Index (BAI) estimates body fat % from hip circumference and height without needing weight. Proposed 2011 as an alternative to BMI.

Formula

BAI = (Hip circumference (cm) / (Height (m))^1.5) − 18; Estimates % body fat without scale (alternative to BMI)

Hip: Hip circumference (Centimeters)
Height: Height (Meters)
BAI: Body adiposity index (Percentage body fat estimate)

Step-by-Step Guide

1BAI = Hip (cm) / Height (m)^1.5 − 18
2Healthy male: 8–20%; Female: 21–33%
3Validated against DXA scan measurements
4No weight scale needed — useful in field settings

Worked Examples

Input

Hip 100cm, height 1.75m

Result

BAI = 100/1.75^1.5 − 18 = 25.3%

Frequently Asked Questions

Why use BAI instead of BMI?

BMI doesn't distinguish fat from muscle. BAI uses hip circumference (fat-specific). Neither perfect: BAI better for lean populations; DEXA scan gold standard.

What's healthy BAI?

Women: 21–32%. Men: 13–25%. Higher = higher visceral fat risk. But BAI underestimates fat in obese populations; use multiple measures.

How do I measure hip circumference?

Around fullest part of hips/buttocks (standing, feet together, relaxed). Slight compression, not tight. Measure 3 times, average. Small error = big impact on BAI.

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