Waist-to-Hip Ratio Calculator
How it works
The ratio is a single division, waist ÷ hip, in whichever unit you entered — no conversion is needed, since the unit cancels out as long as both measurements match.
The World Health Organization sets separate risk bands for men and women:
| Category | Male | Female |
|---|---|---|
| Low | Under 0.90 | Under 0.80 |
| Moderate | 0.90 to under 1.00 | 0.80 to under 0.85 |
| High | 1.00 and above | 0.85 and above |
Unlike BMI, which relates weight to height with no regard for where that weight is carried, waist-to-hip ratio is entirely about fat distribution. The two measure different things and are often looked at side by side rather than as substitutes for one another.
Frequently asked questions
How is this different from BMI?
BMI is weight against height — it says nothing about where on the body that weight sits. Waist-to-hip ratio looks only at fat distribution, comparing waist circumference to hip circumference, so two people with the same BMI can have quite different ratios.
Why do the thresholds differ for men and women?
They come from the World Health Organization's own published reference ranges, which are set separately by sex because typical fat distribution around the waist and hip differs between men and women. Using one shared cutoff for both would misclassify one sex more than the other.
Do I need to convert units first?
No. The ratio is just waist divided by hip, so as long as both measurements are in the same unit — both centimetres or both inches — the unit cancels out of the division and the result is identical either way.