This waist-to-height ratio calculator (WHtR) checks whether your waist is less than half your height, a simple way to assess fat around the middle. Enter your height and waist in centimeters or inches.
Use the same unit for both. For 5 ft 9 in, enter 69 inches.
Why waist-to-height ratio matters
Fat stored around the abdomen is linked with a higher risk of type 2 diabetes, heart disease and high blood pressure. BMI cannot show where fat is stored, so two people with the same BMI can have very different risk. Waist-to-height ratio adds that information, which is why UK guidance from NICE recommends using it alongside BMI for adults.
Formula and categories
Waist-to-height ratio = waist ÷ height (both in the same unit)
- 0.4 to 0.49: healthy central fat
- 0.5 to 0.59: increased health risk
- 0.6 or more: high health risk
How to measure your waist
Stand up straight and breathe out normally. Find the point halfway between your lowest rib and the top of your hip bone, and measure around your body at that level, keeping the tape level and snug without pressing into the skin.
Worked example
Someone who is 175 cm tall with an 85 cm waist has a ratio of 85 ÷ 175 = 0.49. That is in the healthy range, and their waist is 2.5 cm below half their height (87.5 cm).
Frequently asked questions
Is waist-to-height ratio better than BMI?
It answers a different question. BMI relates weight to height; waist-to-height ratio shows fat around the middle. Used together they give a clearer picture than either one alone. You can also check your BMI.
Does the 0.5 rule apply to everyone?
It is designed for adults and works across sexes and many ethnic groups, which is one reason it is popular. It is not intended for children, pregnant women or some athletes without professional advice.
What should I do if my ratio is 0.5 or higher?
It is a sign to look at diet, activity and sleep, and to talk with a doctor, especially if you have other risk factors such as high blood pressure.
This calculator is for information only and is not a medical diagnosis.