Weight check
Waist-to-height ratio calculator
BMI cannot show where fat sits. Your waist measured against your height can. One rule of thumb covers most adults: keep your waist to less than half your height.
Your measurements
Use the same unit for both. Nothing you enter leaves this page.
What you will see
Your ratio, its NICE band, and the waist size that equals half your height.
Educational only, not medical advice. A measurement, not a diagnosis.
Source
NICE guideline NG246, Overweight and obesity management (2025), the UK's national guidance body.
Validated in
Adults with a BMI under 35, of all sexes and ethnicities, including adults with high muscle mass (NICE).
Limits
Not for pregnancy or children. At a BMI of 35 or more, NICE does not use these bands. A tape measure reading can vary by a few centimeters with posture and placement.
The waist-to-height chart
NICE groups the ratio into three bands of central adiposity, meaning fat carried around the middle (NICE NG246):
| Waist-to-height ratio | NICE band | What it means |
|---|---|---|
| 0.4 to 0.49 | Healthy central adiposity | No increased health risk |
| 0.5 to 0.59 | Increased central adiposity | Increased health risks |
| 0.6 or more | High central adiposity | Further increased health risks |
NICE names type 2 diabetes, high blood pressure and cardiovascular disease among the risks linked with higher central adiposity (NICE NG246).
The half-your-height rule
NICE suggests explaining it simply: try to keep your waist to less than half your height, which is a ratio under 0.5 (NICE NG246). Some examples:
| Height | Waist for a ratio of 0.5 | Waist for a ratio of 0.6 |
|---|---|---|
| 5 ft 2 in (62 in) | 31 in | 37.2 in |
| 5 ft 6 in (66 in) | 33 in | 39.6 in |
| 5 ft 10 in (70 in) | 35 in | 42 in |
| 6 ft 2 in (74 in) | 37 in | 44.4 in |
Why add this to BMI?
BMI does not show where in the body fat is carried, or tell fat from muscle (CDC). Waist-to-height ratio looks at the middle, which is where NICE links extra fat with higher health risks. NICE recommends it for adults with a BMI under 35, including people with high muscle mass, for whom BMI alone can mislead (NICE NG246). Work out your BMI too, and read the two together.
How to measure
- Stand up straight and breathe out normally.
- Wrap a tape measure around your bare middle, keeping it level and snug without pressing in.
- Measure your height without shoes, in the same unit.
- Measure the same way each time if you track it.
Common questions
Is the ratio different for men and women?
No. NICE uses the same bands for all sexes and ethnicities (NICE NG246).
Is this a US guideline?
No. NICE is the UK's national guidance body. US agencies such as CDC use BMI categories for adults (CDC), and waist size is often discussed alongside them. We use NICE because it publishes clear, evidence-reviewed cutoffs for the ratio.
What if my BMI is 35 or more?
NICE applies these bands to people with a BMI under 35 (NICE NG246). Above that, talk to your clinician about what to measure.
See also the metabolic syndrome criteria checker, the diabetes risk test and the heart risk calculator.
Sources
- National Institute for Health and Care Excellence. Overweight and obesity management (NG246), section 1.2: Identifying and assessing overweight, obesity and central adiposity. 2025. www.nice.org.uk/guidance/ng246/chapter/Identifying-and-assessing-overweight-obesity-and-central-adiposity
- Centers for Disease Control and Prevention. About Body Mass Index (BMI). www.cdc.gov/bmi/about/index.html
Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-10-28. Spotted an error? See About.