Waist-to-height ratio calculator
Your waist divided by your height says more about the fat around your middle than BMI can. Keep it under 0.5, which means a waist under half your height.
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How to measure your waist
NICE gives this method. Find the bottom of your ribs and the top of your hips, wrap the tape around your waist midway between them, which for most people is just above the belly button, and read it after breathing out naturally. Measure your height without shoes.
The bands
| Ratio | NICE band |
|---|---|
| 0.4 to 0.49 | Healthy central adiposity |
| 0.5 to 0.59 | Increased central adiposity, increased health risks |
| 0.6 or more | High central adiposity, further increased health risks |
NICE’s 2025 obesity guideline uses these bands for adults of both sexes and all ethnicities with a BMI under 35, including people with a lot of muscle. The 0.5 line goes back to Ashwell and Hsieh’s message of 2005: keep your waist circumference to less than half your height.
A boundary, not a cliff
Risk rises gradually with the ratio. The 2010 review that looked at 34 analyses called 0.5 a boundary value on purpose, because it sits on a continuous slope. Going from 0.58 to 0.52 is real progress even before you cross the line. Read more in waist-to-height ratio: keep your waist under half your height.
Sources
- NICE. Overweight and obesity management, guideline NG246, 2025. Recommendations 1.9.5, 1.9.8, 1.9.14 and box 1.
- Ashwell M, Hsieh SD. Six reasons why the waist-to-height ratio is a rapid and effective global indicator for health risks of obesity and how its use could simplify the international public health message on obesity. International Journal of Food Sciences and Nutrition, 2005.
- Browning LM, Hsieh SD, Ashwell M. A systematic review of waist-to-height ratio as a screening tool for the prediction of cardiovascular disease and diabetes: 0.5 could be a suitable global boundary value. Nutrition Research Reviews, 2010.
These calculators give estimates for adults, not a diagnosis. Nothing you type leaves this page.