Waist-to-height ratio calculator

Your waist-to-height ratio is your waist divided by your height. It's one of the simplest checks of fat around the middle — and the rule is easy to remember: keep your waist to less than half your height.

What your ratio means

The UK's National Institute for Health and Care Excellence (NICE) uses these bands for adults: 0.4 to 0.49 means no increased health risk, 0.5 to 0.59 means increased risk, and 0.6 or more means high risk. Below 0.4 may be worth checking that you're not underweight.

It works across sexes and most ethnic groups with the same cut-off, which is part of why guidelines like it.

Why waist-to-height beats BMI as a quick check

BMI only uses weight and height, so it can't see where fat sits. Fat around the abdomen is the type most linked to heart and metabolic problems. A 2012 meta-analysis by Ashwell and colleagues, covering more than 300,000 adults, found waist-to-height ratio was a better screening tool for cardiometabolic risk than either waist circumference or BMI.

NICE now advises adults to measure their waist-to-height ratio alongside BMI, especially with a BMI under 35.

How to measure your waist

Find the point halfway between your lowest rib and the top of your hip bone, which is usually just above the navel. Stand straight, breathe out normally and keep the tape level and snug but not tight. Use the same units for waist and height.

Track your waist without the tape

Trainr measures your waist, hips, chest and more from two photos and charts them over time, next to your body fat estimate. The first scan is free.

Measure your waist from photos — free

Common questions

What is a healthy waist-to-height ratio?

Between 0.4 and 0.49 for adults. In other words, your waist should be less than half your height.

Is waist-to-height ratio better than BMI?

As a screening tool for heart and metabolic risk, research suggests it is, because it reflects abdominal fat. Guidelines recommend using it alongside BMI rather than instead of it.

Is the ratio the same for men and women?

Yes. The 0.5 cut-off works for both sexes, which makes it easy to use.

How fast can I change my ratio?

Waist size responds to fat loss, so it usually moves within weeks of a consistent change in diet and activity. Measure every couple of weeks at the same point.

Keep your waist under half your height, and measure it the same way every few weeks to see where it's heading.

Sources

Ashwell M, Gunn P, Gibson S (2012). Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis. Obesity Reviews. https://pubmed.ncbi.nlm.nih.gov/22106927/
National Institute for Health and Care Excellence (NICE). Overweight and obesity management (NG246). https://www.nice.org.uk/guidance/ng246

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Trainr is a wellness tool, not a medical device. These calculators give estimates for self-tracking, not a diagnosis. For medical questions, talk to a professional.