How it is calculated
WHtR = waist ÷ height WHR = waist ÷ hip| Waist-to-height | Category |
|---|---|
| Below 0.4 | Possibly underweight |
| 0.4 – 0.49 | Healthy |
| 0.5 – 0.59 | Increased risk |
| 0.6 and above | High risk |
The WHO considers a waist-to-hip ratio above 0.90 (men) or 0.85 (women) high risk.
Worked example
Height 170 cm and waist 88 cm: ratio = 88 ÷ 170 = 0.52, “increased risk”; the target is a waist below 85 cm.
Frequently asked questions
Why is it sometimes better than BMI?
It targets belly fat, the most harmful for heart disease and diabetes, while BMI ignores fat distribution.
How do I measure my waist?
Midway between the lowest rib and the top of the hip bone, after a normal breath out.
Does it work for children?
Yes — the “less than half your height” rule is also used for children over 5.