What is Body Adiposity Index (BAI)?

BAI estimates body fat percentage using hip circumference and height, without requiring a weight measurement — unlike BMI.

How is BAI calculated?

BAI = (hip circumference in cm divided by height in meters to the power of 1.5) minus 18, a formula developed as an alternative to BMI for estimating adiposity.

Is BAI more accurate than BMI?

Research is mixed — BAI can better reflect body fat for some populations but isn't universally more accurate than BMI, and neither replaces direct body composition measurement.

Body Adiposity Index (BAI) Calculator

Estimate body fat percentage using only your hip circumference and height.

Hip Circumference (cm)

Height (cm)

Body Adiposity Index -

Category -

What Is the Body Adiposity Index (BAI) Calculator?

Body Adiposity Index (BAI) is an alternative to BMI that estimates body fat percentage from hip circumference and height alone — no bathroom scale needed. It was developed to better reflect body fat in populations where BMI is less accurate.

Formula Used

BAI = (Hip Circumference (cm) ÷ Height (m)^1.5) − 18

BAI approximates body fat percentage directly. It is most reliable for general adult populations and, like BMI, is a screening estimate rather than a diagnostic measurement.

How to Use This Calculator

Measure your hip circumference at the widest point, in centimeters.
Enter your height in centimeters.
Click Calculate to see your estimated BAI and category.

Worked Example

Someone with a 95 cm hip circumference and 170 cm (1.70 m) height has BAI = 95 ÷ (1.70^1.5) − 18 = 95 ÷ 2.217 − 18 ≈ 42.8 − 18 = 24.8%, which falls in the typical/moderate body fat range for adults.