Waist-to-Height Ratio Calculator
Your waist-to-height ratio is one of the best simple screens for health risk, better than BMI in many studies, because it captures belly fat, the kind that drives diabetes and heart disease. The rule is beautifully simple: keep your waist under half your height.
How it's calculated
Waist-to-height ratio = waist ÷ height (same units)
It works in any units as long as both use the same, and it needs no adjustment for sex or ethnicity, one reason health bodies increasingly favour it.1
The categories
- Under 0.5: healthy. Your waist is less than half your height.
- 0.5 to 0.59: increased health risk.
- 0.6 and above: high health risk.
These come from the UK's NICE guideline and apply to both sexes and all ethnicities for adults with a BMI under 35.1
Why it beats BMI
BMI can't tell where your fat sits, and belly fat is the dangerous kind. Waist-to-height ratio measures it directly, catching high-risk people that BMI calls 'healthy' and clearing muscular people that BMI calls 'overweight'.2
Common questions
Where exactly do I measure my waist?
At the navel, with the tape horizontal all the way round. Breathe out normally and stand relaxed, don't pull your stomach in. Measure over bare skin or thin clothing.
Is this better than BMI?
For predicting risks like type 2 diabetes and heart disease, several reviews find waist-to-height ratio as good or better, because it captures belly fat directly. Use both together for the fullest picture.
Does it work for all ethnicities?
Yes, the under-0.5 rule applies across sexes and ethnicities, which is part of why it's so useful. It's validated for adults; children use the same 0.5 rule.
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- National Institute for Health and Care Excellence. Overweight and obesity management. NICE guideline NG246. Published January 2025. Source
- Ashwell M, Gunn P, Gibson S. Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis. Obes Rev. 2012;13(3):275-286. Source
This calculator is general information, not medical advice, and its results are estimates for healthy adults. Speak to a doctor or registered dietitian before making significant changes, especially if you are pregnant or breastfeeding, under 18, or manage a medical condition.
