By ToolzHive
About this tool
The body adiposity index (BAI) estimates body fat percentage without weighing you. Developed by Bergman and colleagues in 2011, it uses only your hip circumference and height: BAI = hip (cm) ÷ height (m)^1.5 − 18. This calculator shows your BAI and compares it with the healthy ranges for your age group and sex.
How to use Body Adiposity Index Calculator
- Choose your units and select your sex.
- Enter your age, height and hip circumference, measured at the widest part of your buttocks.
- Read your BAI and see whether it falls within the healthy range for your age.
Worked example
A woman who is 175 cm tall with 98 cm hips has a BAI of about 24.3%, inside the healthy range of 21–33% for women aged 20 to 39.
Is BAI more accurate than BMI?
BAI estimates body fat directly and does not need a scale, but studies show it is not consistently more accurate than BMI. It works best as one measure among several.
Who should not rely on BAI?
It is less accurate for very lean or very muscular people, older adults and children, because it was developed from specific adult populations.
What is a healthy BAI?
Healthy ranges rise slightly with age. For ages 20–39 they are about 8–21% for men and 21–33% for women.
Put this guide into practice
- Body Adiposity Index Calculator — Estimate body fat from hip size and height with the body adiposity index (BAI).