# Body Adiposity Index Calculator (BAI)

URL: https://speedycalculator.com/calculators/health/body-adiposity-index/
Last updated: 2026-10-25

> The body adiposity index calculator estimates body fat percentage from hip circumference and height, without needing weight. It was proposed in 2011 as an alternative to BMI.

## Inputs

- Hip circumference (cm, m, mm, in, ft)
- Height (cm, m, mm, in, ft)

## Results

- Body adiposity index

## Formula

```
BAI = hip (cm) ÷ height (m)^1.5 − 18
```

## Explanation

BAI was designed to estimate fat percentage directly. Later studies found it is not consistently better than BMI, so treat it as one estimate among several.

### How to use the Body Adiposity Index Calculator

- **Hip circumference**
- **Height**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Divide hip circumference in centimetres by height in metres raised to 1.5, then subtract 18.

### Inputs explained

FieldWhat to enterHip circumferenceUnits: cm, m, mm, in, ftHeightUnits: cm, m, mm, in, ft

### Example values

How the main result changes when **Hip circumference** changes and everything else stays at the example values above:

Hip circumference (cm)Body adiposity index (% body fat)503.67514.410025.21253615046.820068.4
*Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.*

## Worked example

Inputs — Hip circumference: 100 cm; Height: 175 cm.

Results — **Body adiposity index = 25.2 % body fat**.

## FAQ

**Do I need my weight?**
No, only hips and height.

**Is BAI accurate?**
It can over- or under-estimate fat in some groups; compare with other methods.

**What formula does the Body Adiposity Index Calculator use?**
BAI = hip (cm) ÷ height (m)^1.5 − 18.


## Sources

- [Bergman RN et al. A better index of body adiposity. Obesity, 2011](https://pubmed.ncbi.nlm.nih.gov/21372804/)