How waist-to-height ratio calculator works
The waist-to-height ratio (WHtR) compares your waist circumference to your height: you simply divide one by the other, measured in the same unit. Unlike body mass index, it says nothing about weight — it focuses on central fat, the fat stored around your stomach that research links most closely to heart disease and type 2 diabetes risk. Many guidelines now recommend it alongside or instead of BMI because it works across different body frames and heights.
The calculation here follows the widely used rule: keep your waist to less than half your height, which means a ratio below 0.5. The tool places your result into standard bands — below 0.40 is classed as slim (worth checking you are not underweight), 0.40 to 0.49 is healthy, 0.50 to 0.59 indicates increased health risk, and 0.60 or above indicates high health risk. It also converts that 0.5 boundary into a personal target: the largest waist measurement that would still be healthy for your height.
Measure your waist midway between the bottom of your ribs and the top of your hips, usually just above the belly button, after breathing out normally — do not suck your stomach in or pull the tape tight. Enter height and waist in centimetres or inches and the tool does the rest. Everything runs locally in your browser, so your measurements never leave your device, and the result is an educational estimate rather than a medical diagnosis.