Waist-to-Height Ratio: The Simple Check That Complements BMI
Two people with the same BMI can carry fat very differently. Fat around the abdomen is more strongly linked with type 2 diabetes and heart disease than fat on the hips or thighs — and BMI can't see it. Your waist can.
The rule: keep your waist under half your height
The UK's NICE guidance (2022) recommends adults keep their waist-to-height ratio below 0.5:
| Ratio | Meaning |
|---|---|
| 0.40–0.49 | Healthy |
| 0.50–0.59 | Increased risk |
| 0.60 or more | High risk |
Example: waist 88 cm, height 170 cm → 88 ÷ 170 = 0.52, just into the increased-risk band. Half of 170 cm is 85 cm, so the target waist is under 85 cm.
How to measure
- Stand straight and breathe out normally.
- Find the point halfway between your lowest rib and the top of your hip bone.
- Wrap the tape around, level and snug but not squeezing, and read it.
Use the same unit for waist and height — the ratio is the same in cm or inches. The waist-to-height calculator does the division and shows the band.
Why it's useful
- It works across heights without separate charts for men and women.
- It reacts to changes in belly fat that BMI may miss.
- It's easy to track at home every few weeks.
It's validated for adults; it isn't meant for pregnancy, and children use different references. Use it together with BMI, not instead of medical advice.