BAI Calculator – Body Adiposity Index

Written by Great Medico

Updated September 24, 2026 •2 min read

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One body-size number rarely tells the whole story, but it can answer a precise question. BAI Calculator – Body Adiposity Index is built for that narrower job.

What this calculator does

The Body Adiposity Index, or BAI, estimates body adiposity from only two measurements: height and hip circumference. It can be useful when a scale-derived body-fat estimate is unavailable. Anthropometric equations are convenient because they use simple measurements, but they describe body size or proportion rather than directly measuring tissue composition or health.

How to use it

Enter or select Your height and Your hip circumference. Use the units offered by the calculator and keep measurements consistent when you plan to compare results over time.

How the calculation works

BAI is calculated as hip circumference in centimeters divided by height in meters raised to the 1.5 power, minus 18. The calculator converts supported units before applying the equation.

Example

For the sample values prefilled in this calculator, the primary result is 23.04 % (Body adiposity index). This example is there to show how the inputs flow through the implemented equation; replace the sample values with your own measurements before using the result.

How to interpret the result

The percentage-like output is an estimate of adiposity, not a laboratory or imaging measurement of body fat. It is best used as a rough context value or to follow measurements consistently over time.

Limitations and notes

BAI accuracy varies across populations and body types, and research has found that it does not consistently outperform BMI or direct body-composition methods. Hip measurement technique can also shift the result, so use the same anatomical landmarks each time. For repeat measurements, consistency usually matters more than false precision: use the same unit system, the same tape or scale when possible, and the same anatomical landmarks. A small change near a category boundary should be viewed in context rather than treated as a sudden biological change.