What is the waist-to-height ratio?
The waist-to-height ratio (WHtR) is your waist circumference divided by your height. It is one of the simplest and most useful ways to check for central obesity — harmful fat stored around the abdomen and organs. The message is easy to remember: keep your waist to less than half your height.
In 2022 the UK’s National Institute for Health and Care Excellence (NICE) recommended that adults with a BMI under 35 measure their waist-to-height ratio as well as BMI. Research shows WHtR predicts type 2 diabetes, high blood pressure and heart disease at least as well as — and often better than — BMI, and the same cut-off works for women, men and different ethnic groups, including South Asian adults.
How the calculator works
Waist-to-height ratio = waist (cm) ÷ height (cm) — or both in inches.
Example: a man 175 cm tall with a 92 cm waist has a WHtR of 92 ÷ 175 = 0.53 (increased risk). To get under 0.5 his waist would need to be under 87.5 cm.
How to measure your waist
- Find the bottom of your lowest rib and the top of your hip bone; measure halfway between them.
- Stand relaxed, breathe out normally and do not hold your stomach in.
- Keep the tape level all the way round, snug but not pressing into the skin.
Waist-to-height ratio chart
| WHtR | Category (NICE) | Level |
|---|---|---|
| Below 0.40 | Low — check you are not underweight | Low |
| 0.40 – 0.49 | Healthy central adiposity | Normal |
| 0.50 – 0.59 | Increased central adiposity — increased health risk | High |
| 0.60 and above | High central adiposity — further increased risk | Very high |
Healthy waist size by height (ratio 0.5)
| Height | Keep waist below |
|---|---|
| 150 cm (4′11″) | 75 cm (29.5″) |
| 160 cm (5′3″) | 80 cm (31.5″) |
| 170 cm (5′7″) | 85 cm (33.5″) |
| 180 cm (5′11″) | 90 cm (35.4″) |
| 190 cm (6′3″) | 95 cm (37.4″) |
Benefits of checking your waist-to-height ratio
- One rule for everyone: the 0.5 cut-off works for women and men of all heights and most ethnic backgrounds.
- Catches risk that BMI misses, such as “skinny fat” or belly fat in people with a normal BMI.
- A motivating measure: your waist often shrinks before the scale moves, especially when you start strength training.
- Takes 30 seconds with a piece of string: if string the length of your height, folded in half, does not fit around your waist, your ratio is over 0.5.
Health warnings
- This is a screening measure, not a diagnosis. A ratio of 0.5 or above is a reason to check blood sugar, blood pressure and cholesterol.
- Not valid during pregnancy, and the cut-offs differ for children under 5.
- Bloating, a large meal or abdominal conditions can temporarily increase your waist — measure in the morning before eating.
- Very muscular people with large backs may show slightly higher readings.
How to bring your ratio below 0.5
Focus on overall fat loss with a modest calorie deficit (calorie calculator), cut sugary drinks and refined carbs, eat more fibre and protein, and include brisk walking and strength training. Alcohol, poor sleep and stress also increase belly fat. Track your waist every 2–4 weeks alongside your waist-to-hip ratio and BMI.
Frequently asked questions
What is a healthy waist-to-height ratio?
A ratio between 0.40 and 0.49 is healthy for adults. A ratio of 0.50–0.59 means increased health risk, and 0.60 or more means high risk.
Is waist-to-height ratio better than BMI?
It often predicts the risk of diabetes and heart disease better than BMI because it reflects belly fat. NICE recommends using both together for adults with a BMI under 35.
Does the 0.5 rule apply to women and men?
Yes. The same 0.5 boundary applies to women and men and to people of different ethnic backgrounds, including South Asian and Middle Eastern adults.
Can children use the waist-to-height ratio?
A ratio above 0.5 is also a useful warning sign in children over 5 and teenagers, but children should be assessed with BMI-for-age charts by a health professional.
How quickly can I lower my waist measurement?
Many people lose 1–2 cm from their waist in the first month of a balanced diet and regular exercise. Progress continues gradually as you lose body fat.
Sources
- NICE. Obesity: identification, assessment and management (CG189), updated 2022 — waist-to-height ratio recommendation.
- Ashwell M, Gunn P, Gibson S. Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors. Obes Rev 2012;13:275–286.