Free waist health tool
Waist Check: Waist Circumference and Ratio Calculator
Enter your waist, and optionally your height and hips, to see three common measures side by side: waist circumference, waist-to-height ratio, and waist-to-hip ratio. It works in centimeters and inches.
For adults aged 18 and over. A screening measure, not a diagnosis. Nothing you enter is stored or sent anywhere.
This tool gives general screening information, not a medical assessment. Results are calculated in your browser and are not stored or sent to us. See the disclaimer.
How to measure your waist, step by step
- Use a soft tape measure and stand up straight, relaxed.
- Find the lowest part of your ribs and the top of your hip bones. Your waist is halfway between the two. Your belly button is often close to this point.
- Breathe out naturally, then wrap the tape snugly around your waist at that point. It should be level all the way around and snug, without squeezing.
- Read the number without holding your breath or pulling your stomach in. For the hip measurement, wrap the tape around the widest part of your buttocks.
- Measure over bare skin or thin clothing so the tape lies flat. Measuring twice and using the average reduces mistakes.
The halfway-point method and the instruction to breathe out naturally come from Northern Ireland’s Public Health Agency. The point about clothing and measuring twice is practical advice rather than a health claim.
What the three measures mean
| Measure | What it compares | Reference points used here | Source |
|---|---|---|---|
| Waist circumference | The distance around your waist on its own | Men: 94 cm (37 in) and 102 cm (40 in). Women: 80 cm (31.5 in) and 88 cm (35 in) | NHS, Public Health Agency (NI), NIDDK |
| Waist-to-height ratio | Your waist divided by your height | Keep your waist to less than half your height (ratio below 0.5) | NHS |
| Waist-to-hip ratio | Your waist divided by your hips | Men: 0.90. Women: 0.85 | WHO |
Each measure answers a slightly different question, so we show them together instead of picking one. If you want more detail on the height ratio, read What Is Waist-to-Height Ratio? or use the dedicated waist-to-height ratio calculator.
What these numbers cannot tell you
- They are not a diagnosis. A waist measurement is a screening measure. It cannot tell you whether you have, or do not have, a health problem.
- Body shape and background differ. The NHS suggests a lower waist figure for men of Black African, African Caribbean, South Asian or Middle Eastern background, which shows that one set of numbers does not fit everyone.
- Some people should not rely on them. The measures are designed for adults. They are not meant for children or teenagers, and pregnancy changes the waist.
- Measuring technique matters. A few centimeters can come from where the tape sits, how tight it is and whether you breathed in or out.
For general information only. If you are worried about your waist size or your health, speak to your doctor or nurse. See our disclaimer.
Frequently asked questions
What is a healthy waist size?
The NHS gives 94 cm (37 inches) for men and 80 cm (31.5 inches) for women as the figures to stay below. NIDDK says 40 inches or more for men and 35 inches or more for women is linked with a higher risk of obesity-related health problems. These are guides, not a pass or fail.
Which measure is the best one to use?
No single measure is perfect. Waist circumference needs only a tape measure. The height ratio also takes your height into account, and the hip ratio compares your waist with your hips. That is why this tool shows all three together.
What should I do if my waist is above the reference points?
Treat it as information, not a verdict. If you are concerned, talk to your doctor or nurse, who can look at your whole health picture. For general, sourced reading, see what health authorities say about belly fat and what the research says about walking.
Why does my waist change as I get older?
We explain what is known, with sources, in Why Your Waist Grows With Age.
Is my data stored?
No. The calculation runs in your browser. The numbers you type are not stored or sent to us.
Sources
- NHS (My Health London): Measurements matter (waist figures of 94 cm for men and 80 cm for women; 90 cm for men of Black African, African Caribbean, South Asian and Middle Eastern background)
- NHS: Calculate your waist to height ratio (keep your waist to less than half your height)
- NIDDK: Am I at a healthy weight? (35 inches or more for women and 40 inches or more for men)
- Public Health Agency (Northern Ireland): Are you inching towards bad health? (how to measure your waist)
- World Health Organization: Waist circumference and waist-hip ratio, report of a WHO expert consultation (2008) (waist-to-hip reference points)
Last reviewed: October 15, 2026. Guidance can change. This page is general information and not medical advice.