Waist-to-Height Ratio Calculator

Around the midpoint between the bottom of your ribs and the top of your hip bones — roughly at the navel for most people. Stand relaxed, breathe out normally, and keep the tape snug but not compressing the skin. Measure on bare skin for consistency.

BMI uses only weight and height, so it can’t tell where fat sits and is thrown off by muscle. WHtR targets central (abdominal) fat, which is more closely linked to heart and metabolic risk. Many researchers consider it a better quick screen — and it’s just as easy to work out.

Under 0.5 for most adults. The simplest way to remember it: your waist should be less than half your height. Below about 0.4 may indicate you’re underweight around the middle, which is worth discussing with a doctor.

It’s a good general cut-off for adults of both sexes and most ethnicities, which is part of its appeal. Children use age-adjusted charts, and some populations use slightly lower thresholds, so treat it as a screen rather than a precise line.

Not necessarily. A ratio well below 0.4 can reflect being underweight, which carries its own risks. The healthiest range sits between roughly 0.4 and 0.5, which is why the tool flags very low values too.

The ratio itself is unit-free, so inches would give the same number — but the healthy waist range shown assumes centimetres. For that range to make sense, enter both measurements in centimetres.

Monthly is plenty. Body measurements move slowly, so measure under the same conditions each time — same time of day, same tape position — and watch the trend rather than day-to-day noise.

No. It’s a screening estimate. A rising ratio is a useful prompt to look at diet, activity and other risk factors, but only a clinician can assess your health properly.

Yes. The calculation runs entirely in your browser; nothing is uploaded and analytics never sees your figures.