About the Waist to Height Ratio Calculator
The waist-to-height ratio compares the distance round your waist with your height. A simple rule says to keep your waist below half your height, which is a ratio below 0.5. Researchers find that the ratio predicts health risks linked to belly fat at least as well as BMI does, and it needs only a tape measure. This calculator gives your ratio, your health band and the waist size that would be exactly half your height. Type your waist and your height and the waist-to-height ratio appears at once, with a few related figures underneath, and you can copy the result with one tap. The sums run in your browser, so nothing you enter is uploaded.
Updated October 2026
How to use the Waist to Height Ratio Calculator
- 1Enter your waist and your height.
- 2Pick the units or options from the menus if the waist-to-height ratio tool offers them.
- 3Read the waist-to-height ratio in the large result box.
- 4Look at the extra rows for related figures.
- 5Press Copy result to keep the answer.
When you need the waist-to-height ratio
Doctors and fitness coaches like the ratio because it works across heights, so it is as useful for short as for tall people, and it needs no tables for age or sex. It is also easy to track: you can see progress by measuring your waist every few weeks.
Measure the waist at the level of the navel or halfway between the lowest rib and the top of the hip bone, standing relaxed and breathing out. Measure your height without shoes. Use the same unit for both numbers.
How the waist-to-height ratio is worked out
Ratio = waist ÷ height, both in the same unit. Below 0.4 is on the slim side, 0.4 to 0.49 is the healthy range, 0.5 to 0.59 means raised risk, and 0.6 or more means high risk. A person 175 cm tall with an 85 cm waist has a ratio of 85 ÷ 175 = 0.486, in the healthy range, and their half-height target is 87.5 cm. Someone 170 cm tall with a 100 cm waist has 0.588, in the raised risk band, and would need to lose about 15 cm round the waist to reach 0.5.
Every answer on this page comes from that one rule, so you can check any result by hand with a calculator. The figures shown underneath, such as other units, are conversions of the same answer.
- Centimetres or inches
- Health band shown
- Waist target for a ratio of 0.5
Mistakes to avoid with waist-to-height ratio
It is a screening tool, not a diagnosis. Muscular people, pregnant women, children and some ethnic groups may need different cut-offs. If your ratio is high, speak to a doctor, who can look at blood pressure, blood sugar and cholesterol too.
On phone and computer
On a phone, type into the boxes one after another and read the waist-to-height ratio underneath; Copy result puts it on the clipboard for a message or a note. On a computer the inputs sit on the left and the answer on the right, so you can change one figure and watch the waist-to-height ratio move. The waist to height ratio calculator works the same on both. Add more body checks with BMI Calculator, Body Fat Calculator and Waist-to-Hip Ratio Calculator, and use Ideal Weight Calculator to compare your numbers with common guidance.
Features
- Breathe out when measuring
- Same unit for both numbers
- A screening measure only
- Clear messages when the waist-to-height ratio inputs make no sense
- Copy the result with one tap
- Private: nothing is uploaded
Frequently asked questions
How do I calculate waist-to-height ratio?
Ratio = waist ÷ height, both in the same unit. Below 0.4 is on the slim side, 0.4 to 0.49 is the healthy range, 0.5 to 0.59 means raised risk, and 0.6 or more means high risk. A person 175 cm tall with an 85 cm waist has a ratio of 85 ÷ 175 = 0.486, in the healthy range, and their half-height target is 87.5 cm. Someone 170 cm tall with a 100 cm waist has 0.588, in the raised risk band, and would need to lose about 15 cm round the waist to reach 0.5.
What is the formula for waist-to-height ratio?
Ratio = waist ÷ height, both in the same unit. Below 0.4 is on the slim side, 0.4 to 0.49 is the healthy range, 0.5 to 0.59 means raised risk, and 0.6 or more means high risk. The waist to height ratio calculator applies it exactly and rounds only the displayed answer to six significant figures.
What is a healthy waist-to-height ratio?
For most adults, 0.4 to 0.49. Keeping it below 0.5 is the usual advice.
Is it better than BMI?
It measures where fat sits, which matters for health, while BMI cannot tell fat from muscle. Many experts suggest using both.
Does it apply to children?
The same 0.5 guide is used for children over 5 in many studies, but ask a paediatrician for advice.
Is this waist to height ratio calculator free and private?
Yes. It is free, needs no account and runs in your browser, so the numbers you type are not uploaded or stored.