The waist-to-height ratio (WHtR) is your waist divided by your height. It's a quick screen for central obesity, and the message is simple: keep your waist to less than half your height — a ratio under 0.5. This calculator returns the ratio, your risk band, and the waist that keeps you under the cut-off.
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: Ashwell WHtR boundary values, recomputed in code.
The ratio & bands
Because it's a ratio, the units cancel — centimetres or inches give the same number. Widely used boundaries are: below 0.4 may indicate underweight (worth a review); 0.4 to under 0.5 is healthy; 0.5 to under 0.6 is increased risk; and 0.6 or more is high risk. WHtR captures abdominal fat, which is why many researchers consider it at least as informative as BMI.
Worked examples
80 cm waist, 170 cm height:
95 cm waist, 175 cm height:
34 in waist, 70 in height:
The healthy maximum waist is always half your height: 85 cm for someone 170 cm tall, or 35 in for someone 70 in tall. Staying below that keeps the ratio under 0.5.
Frequently Asked Questions
Waist ÷ height in the same unit. Keep it under 0.5 — waist under half your height.
0.4 to just under 0.5. 0.5–0.6 increased risk; 0.6+ high risk; below 0.4 worth reviewing.
Divide waist by height. 95 cm ÷ 175 cm = 0.54.
Often comparable or better — it reflects abdominal fat. Both are screens, not diagnoses.
Narrowest point between lowest rib and hip bone, near the navel, after a normal breath out.