Waist-to-Height Ratio Risk Calculator
Divide your waist by your height to get the waist-to-height ratio (WHtR) and see which cardiometabolic risk band the "keep your waist under half your height" rule places you in.
How it works
WHtR = waist circumference ÷ height (same units)
The waist-to-height ratio is one of the strongest simple predictors of cardiometabolic risk because it focuses on fat stored around the abdomen, which is more metabolically active than fat elsewhere. Unlike BMI it does not need a sex or age adjustment: the boundary "keep your waist to less than half your height" (a ratio of 0.5) works across adults. Ratios climbing toward 0.6 and beyond signal rising risk of type 2 diabetes and heart disease. It is a screening signal, not a diagnosis.
Worked example
A person with an 84 cm waist and a height of 175 cm has WHtR = 84 ÷ 175 = 0.48 — just under 0.5, inside the healthy band, and about 3.5 cm below the "half your height" target of 87.5 cm.
Sources: Ashwell M. et al. — Waist-to-height ratio review (NIH/PubMed)
Frequently asked questions
Why use waist-to-height instead of BMI?
BMI treats all weight the same and can misclassify muscular or short people. Waist-to-height ratio isolates abdominal fat, which drives most of the metabolic risk, and uses one threshold for everyone: keep your waist under half your height.
Where should I measure my waist?
Measure around the narrowest point, usually at the navel, at the end of a normal breath out, without pulling the tape tight. Use the same spot each time so changes are comparable.
What ratio should I aim for?
Below 0.5 is the healthy target for most adults. Between 0.5 and 0.6 suggests increased risk, and 0.6 or above suggests high risk worth discussing with a clinician.
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Educational estimate, not medical advice — for personal health decisions consult a qualified healthcare professional.