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How to measure your waist
NICE describes the method: find the bottom of your ribs and the top of your hips, wrap a tape measure around your waist midway between them (usually just above your belly button), and breathe out naturally before reading it. Use the same units for waist and height. The NHS obesity page has a short video guide.
What your ratio means
| Waist-to-height ratio | What NICE says |
|---|---|
| 0.4 to 0.49 | Healthy — no increased health risks |
| 0.5 to 0.59 | Increased central fat — increased health risks |
| 0.6 or more | High central fat — further increased health risks |
NICE says these bands apply to adults with a BMI under 35, of both sexes and all ethnicities, including people with high muscle mass. The simple message is to keep your waist to less than half your height.
Why waist matters alongside BMI
BMI can't tell where you carry weight. Fat stored around the middle is linked to type 2 diabetes, high blood pressure and heart disease, which is why NICE recommends measuring waist-to-height ratio alongside BMI.
What to do next
- 0.5 or above: small, steady changes to eating and activity help. Free support is available through your GP, family doctor or primary-care clinician; see free care routes.
- 0.6 or above: ask about checks for diabetes and heart risk, such as HbA1c and cholesterol; in England, adults aged 40 to 74 can have a free NHS Health Check.
Common questions
What is a healthy waist-to-height ratio?
NICE classes 0.4 to 0.49 as healthy, meaning no increased health risk. A ratio of 0.5 to 0.59 indicates increased risk, and 0.6 or more indicates further increased risk. The simplest way to remember it is to keep your waist to less than half your height.
Is waist-to-height ratio better than BMI?
It measures something different. BMI compares weight with height, while waist-to-height ratio shows how much fat you carry around the middle, which is more closely linked to diabetes and heart disease. NICE recommends using both for adults with a BMI under 35, rather than one instead of the other.
Does waist-to-height ratio work for everyone?
NICE says the bands can be used for adults with a BMI under 35 of both sexes and all ethnicities, including people with high muscle mass. They aren't meant for pregnancy or for children. Above a BMI of 35, health risks are high anyway, so waist measurement adds less.
Where exactly should I measure my waist?
Find the bottom of your ribs and the top of your hip bones, then wrap the tape measure around your middle halfway between them, which is usually just above your belly button. Stand relaxed, breathe out naturally and read the tape without pulling it tight. Measure your height in the same units.
Sources
- NICE. Overweight and obesity management (NG246): identifying and assessing overweight, obesity and central adiposity. 2025.
- NHS. Obesity — how to measure your waist and get support.
- NHS. NHS Health Check.
General information, not medical advice — see our medical disclaimer. These results are estimates and can't diagnose anything. In an emergency, call 911 (US, Canada) or 999 (UK).