Enter your waist and hip measurements to find your waist-to-hip ratio and see how it compares with the WHO thresholds. Add your height for the waist-to-height ratio.
Results are estimates for planning. Check the figures before you make a financial or health decision.
How the Waist-to-hip ratio calculator works
Waist-to-hip ratio = waist ÷ hips, using the same unit for both. You can enter centimetres or inches.
The tool compares the result with the thresholds commonly published by the WHO: a ratio of 0.85 or above in women and 0.90 or above in men indicates abdominal obesity and increased health risk. Below those values it shows as below the threshold.
If you also enter your height it works out the waist-to-height ratio (waist ÷ height), which the NHS uses as a simple check: keeping your waist to less than half your height. The tool also shows the waist size that would be half your height.
Measurements must be realistic (waist 40 to 250 cm, hips 50 to 250 cm). Both ratios are screening guides and cannot diagnose a condition.
Worked example
Using the default values in the calculator above:
| Input | Value |
|---|---|
| Units | Centimetres |
| Sex | Female |
| Waist | 82 |
| Hips | 100 |
| Height (optional) | 168 |
Waist-to-hip ratio: 0.82
| WHO threshold for women | 0.85 or above indicates increased risk |
|---|---|
| Waist-to-hip band | Below the WHO threshold |
| Waist-to-height ratio | 0.49 |
| Compared with the 0.5 guide | Waist is less than half your height |
| Waist under half your height would be | 84 cm or less |
| Waist | 82 cm |
Tips and common mistakes
Measure with a soft tape on bare skin or thin clothing, standing relaxed and breathing out normally. Do not pull the tape tight. For the waist, measure halfway between the bottom of your ribs and the top of your hips; for the hips, around the widest part. Measure twice and use the average. The ratios are less reliable in pregnancy, for older people and for some ethnic groups, so use them with BMI and other signs. If a result concerns you, speak to a GP or practice nurse. This is general information, not medical advice.
Frequently asked questions
What is a healthy waist-to-hip ratio?
The WHO treats below 0.85 for women and below 0.90 for men as under the threshold for increased risk. These are guides rather than diagnoses.
Is waist-to-hip ratio better than BMI?
They measure different things. BMI ignores where fat is carried, while waist ratios look at fat around the middle. Using both gives a fuller picture.
What is the waist-to-height ratio rule?
The NHS suggests keeping your waist to less than half your height, which is a ratio below 0.5. It is a quick check, not a diagnosis.
Guides that help
- BMI explained: what it tells you and what it doesn't
- Body fat percentage: how it's measured and what's typical