Waist to Height Ratio — The Metric That Beats BMI (2026)

Waist-to-height ratio takes ten seconds with a tape measure and predicts cardiometabolic risk better than BMI. The target is simple: keep your waist under half your height.

The formula

WHtR = waist ÷ height, in the same units. A 90 cm waist with 180 cm height gives 0.50 — right at the threshold.

How to measure your waist correctly

Measure at the midpoint between the lowest rib and the top of the hip bone, at the end of a normal exhale, tape snug but not compressing. Not at the trouser line.

Interpreting your ratio

Under 0.40 = possibly underweight · 0.40–0.49 = healthy · 0.50–0.59 = increased risk · 0.60+ = high risk. The same boundaries apply to men and women and across ethnicities.

Why it beats BMI

It measures central (visceral) fat, which drives insulin resistance and cardiovascular disease. BMI cannot distinguish visceral fat from muscle; WHtR largely can.

UK NICE guidance

NICE recommends WHtR alongside BMI for adults with BMI under 35, exactly because BMI misses central adiposity in normal-weight individuals.

Using both together

Normal BMI plus WHtR above 0.5 is the 'normal-weight obesity' pattern worth acting on. High BMI plus WHtR under 0.5 usually indicates muscle mass, not risk.

Sources & further reading

BIPM — The International System of Units (SI Brochure)
NIST — Guide for the Use of the International System of Units
WHO — Body weight & health guidance

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