Waist-to-Height Ratio Calculator
Waist รท height with NICE health bands and the waist size to stay under.
About this tool
Enter your height and waist in centimetres or inches, and choose female or male for the waist-only thresholds. The calculator shows your waist-to-height ratio, the health band it falls in, the waist measurement that would keep the ratio under 0.5, and how your waist compares with the standard waist-circumference thresholds.
What waist-to-height ratio tells you
Waist-to-height ratio is your waist divided by your height, in the same units. The message is simple: keep your waist to less than half your height. Someone 175 cm tall with an 84 cm waist has a ratio of 0.48, inside the healthy band, and staying below 87.5 cm keeps it under 0.5. The UK's NICE guideline uses these bands for adults: 0.4โ0.49 is healthy, 0.5โ0.59 means increased health risks and 0.6 or more means further increased risks. Below 0.4 may mean you are underweight. The ratio reflects fat around the middle, which is linked more closely to type 2 diabetes and heart disease than overall weight, so NICE recommends measuring it alongside BMI for adults with a BMI under 35. To measure, place the tape halfway between your lowest rib and the top of your hip bone, breathe out normally and keep the tape snug but not tight. Honest limits: the bands are for adults. Children, pregnant women and very muscular people need a professional assessment, and no single number sums up your health. Not medical advice. The BMI calculator gives the other half of the picture, the body fat calculator estimates fat percentage and the ideal weight calculator shows common formulas. Is BMI accurate? explains why BMI alone can mislead.
Frequently asked questions
What is a healthy waist-to-height ratio?
Between 0.4 and 0.49 for adults. In other words, a waist less than half your height.
How do I measure my waist for this?
Halfway between your lowest rib and the top of your hip bone, after breathing out normally, with the tape level and snug.
Is waist-to-height ratio better than BMI?
It is a better guide to fat around the middle, which carries more health risk. NICE recommends using both for most adults.
Is my data saved?
No. The calculation runs in your browser and nothing is stored or sent.