Waist-to-height ratio is a measurement divided by another measurement. This tool returns the number and explains the arithmetic; it does not classify your health or recommend treatment.
Calculate waist-to-height ratio
Your entries stay in this browser. They are not submitted or saved. This calculation is information, not a diagnosis or a treatment recommendation.
The formula and units
Waist-to-height ratio = waist circumference ÷ height. Both measurements must use the same unit: centimetres with centimetres, or inches with inches. The result has no unit.
A worked example
An illustrative waist circumference of 90 cm and height of 180 cm give 90 ÷ 180 = 0.50. This is an arithmetic example, not a diagnosis.
Measurement matters
NICE describes measuring around the midpoint between the lower ribs and the top of the hips, after breathing out normally. Its guidance also describes how the measure fits into an assessment. Inconsistent tape placement can change the result.
What this number cannot tell you
A single measurement does not describe your medical history or establish what care is appropriate. Pregnancy and other circumstances can affect interpretation. This tool provides no diagnosis, risk category, target waist or treatment recommendation.
Sources and related reading
NICE: identifying and assessing overweight, obesity and central adiposity explains the measurement and its assessment context.
See the percentage weight-loss calculator, our weight-management guide and the medical disclaimer. Your inputs remain in the browser and are not saved or sent to analytics.