Waist-to-Height Ratio Calculator
One tape measure, one number: check whether your waist is less than half your height.
Quick answer
Waist-to-height ratio = waist ÷ height, in the same units. Under UK NICE guidance for adults, 0.4 to 0.49 is healthy, 0.5 to 0.59 means increased health risk, and 0.6 or more means high risk. Someone 175 cm tall should keep their waist under 87.5 cm; someone 5′9″ (69 in) under 34.5 inches.
Halfway between your lowest rib and the top of your hip bone.
Waist-to-height ratio
0.48
- Result
- Healthy
- Keep your waist under
- 87.5 cm
NICE adult guidance: keep your waist to less than half your height. Not a diagnosis.
Healthy waist size by height (ratio under 0.5)
| Height | Keep waist under |
|---|---|
| 150 cm (4′11″) | 75 cm (29.5 in) |
| 155 cm (5′1″) | 77.5 cm (30.5 in) |
| 160 cm (5′3″) | 80 cm (31.5 in) |
| 165 cm (5′5″) | 82.5 cm (32.5 in) |
| 170 cm (5′7″) | 85 cm (33.5 in) |
| 175 cm (5′9″) | 87.5 cm (34.4 in) |
| 180 cm (5′11″) | 90 cm (35.4 in) |
| 185 cm (6′1″) | 92.5 cm (36.4 in) |
| 190 cm (6′3″) | 95 cm (37.4 in) |
How it works
Waist-to-height ratio compares the fat stored around your middle with your height. Fat around the abdomen is linked more closely to type 2 diabetes, high blood pressure and heart disease than weight alone, which is why UK health guidance now recommends measuring it alongside BMI. The message is simple: keep your waist to less than half your height.
Measure your waist halfway between your lowest rib and the top of your hip bone — usually just above the belly button — breathing out normally, with the tape snug but not tight. Use the same units for waist and height; the ratio is the same in centimetres or inches.
The ratio works for adults of all ethnic backgrounds and sexes, and is especially useful for people whose BMI is misleading — muscular people can have a high BMI but a healthy waist, while some people with a normal BMI carry risky fat around the middle. It is a screening tool, not a diagnosis: if your ratio is 0.5 or above, a doctor can check your blood pressure, blood sugar and cholesterol.
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Frequently asked questions
What is a good waist-to-height ratio?
Between 0.4 and 0.49 for adults. A ratio of 0.5 or more means increased health risk.
Is waist-to-height ratio better than BMI?
It is a better sign of fat around the organs, which drives much of the health risk. Doctors increasingly use both together.
Does the ratio apply to children?
The 0.5 cut-off is often used for children over 5 too, but guidance for children differs, so speak to a health professional.