Body Adiposity Index Calculator

Estimate body fat percentage from hip circumference and height, without needing a scale.

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Height (m)

Hip circumference (cm)

Result

Enter values to calculate.

Summary

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Detail

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Estimate body fat percentage from hip circumference and height, without needing a scale.

How It Works

How Body Adiposity Index Calculator Works

BAI was developed as an alternative to BMI that doesn't require stepping on a scale — it estimates body fat using just hip circumference and height, on the idea that hip size correlates with body fat percentage in adults.

Worked Example

See It In Action

A height of 1.8 m and hip circumference of 102 cm gives a BAI of about 24.2, which falls in the range generally considered a healthy body fat level.

Real-World Use Cases

Who Uses Body Adiposity Index Calculator and Why

Getting a body fat percentage estimate when you don't have access to a reliable scale, since BAI only needs height and hip circumference.
Comparing your BAI result against a BMI result to see how the two different methods classify the same body.
Tracking hip circumference changes over time as a proxy for body fat trend, using BAI as the conversion.
Providing a quick, scale-free estimate in settings (like fieldwork or travel) where weighing isn't practical.

Common Mistakes

Mistakes to Avoid

Assuming BAI is a more accurate substitute for BMI in all cases — the calculator's own FAQ notes studies show mixed results on which correlates better with actual body fat, so neither should be treated as definitive.
Measuring hip circumference inconsistently (a different point on the hips, a different tightness of the tape) between measurements, which undermines tracking BAI change over time.
Using the BAI result to diagnose or manage a health condition without professional input — it's a population-level estimation formula, not a diagnostic measurement of actual body fat.

Pro Tips

Tips for Best Results

Measure hip circumference at the widest point of your hips/buttocks for a consistent, comparable reading each time.
If you have access to both a scale and a tape measure, compare your BAI result against BMI and note where they agree or disagree rather than trusting either number alone.

Troubleshooting

Fixing Common Problems

My BAI and BMI results seem to disagree quite a bit. — This isn't unusual — the two formulas use entirely different inputs (BAI uses hip circumference and height; BMI uses weight and height) and were derived differently, so some disagreement between them is expected rather than a sign either result is wrong.

Glossary

Terms Explained

BAI (Body Adiposity Index): A body fat estimation formula developed as a scale-free alternative to BMI, using only hip circumference and height.

FAQ

Frequently Asked Questions

How is this different from BMI?

BMI uses height and weight, while BAI uses height and hip circumference instead of weight — it was designed as an option for situations where a reliable scale isn't available.

Is BAI more accurate than BMI?

Neither is a direct measurement of body fat — both are estimates, and studies have found mixed results on which correlates better with actual body fat across different populations, so treat either as a general indicator rather than a precise reading.