Body Adiposity Index Calculator
Body fat estimated from hip size and height, no weight needed.
At the widest point across the buttocks.
Validation against DEXA has been mixed, and BAI tends to overestimate in men. Treat it as a field estimate and confirm anything surprising with another method.
Estimated body fat (BAI)
25.2%
No weight is needed, which is the whole point of this index — it was designed for field studies where scales are impractical.
How the Body Adiposity Index Calculator works
The body adiposity index, proposed in 2011, estimates body fat from hip circumference and height alone. Its appeal is that it needs no scale, which matters in field studies and low-resource settings. Its drawback is that later validation has been mixed.
Not medical advice. This calculator gives a general estimate, not medical advice. It cannot account for your individual health, medical history, or medication. Talk to a qualified healthcare professional before acting on any result.
Frequently asked questions
How is the body adiposity index calculated?
BAI = hip circumference in cm ÷ (height in metres)^1.5 − 18. The result is read directly as an estimated body fat percentage.
How accurate is BAI?
Less accurate than its authors hoped. Subsequent studies comparing it against DEXA have generally found it no better than BMI, and often worse in men, where it tends to overestimate. Treat it as a rough field estimate rather than a measurement.
Why would I use BAI over BMI?
The main practical reason is that it does not need a scale — only a tape measure. It also captures hip size directly, so it responds to fat distribution in a way BMI cannot. If you can weigh yourself, the US Navy tape method is generally the better choice.
What is a healthy BAI?
Because BAI reads as a body fat percentage, the usual body fat ranges apply: roughly 8–20% for men and 21–33% for women depending on age. Given the accuracy concerns, confirm anything surprising with a second method.