Waist-to-Height Ratio Calculator

Waist-to-height ratio (WHtR) is simply waist circumference ÷ height, measured in the same unit (both inches or both cm). It's a proxy for central adiposity — fat carried around the abdomen — which tracks more closely with cardiometabolic risk than total body size alone.

We use the classification bands from the UK's National Institute for Health and Care Excellence (NICE) guideline NG246 (2025), recommendation 1.9.14:

• 0.40–0.49 — Healthy central adiposity, no increased health risk
• 0.50–0.59 — Increased central adiposity, increased health risk
• 0.60 or more — High central adiposity, further increased health risk

NICE states these bands can be used for adults with a BMI under 35 kg/m², of both sexes and all ethnicities, including adults with high muscle mass — above that BMI, other assessment methods take over, since the calculator becomes less useful at that point. NICE also gives a plain-language version of the same threshold, worth remembering on its own: try to keep your waist circumference to less than half your height (a ratio under 0.5).

How to measure your waist: find the bottom of your ribs and the top of your hip bone, then wrap the tape measure around your waist midway between the two — roughly level with your belly button. Keep the tape snug against the skin without compressing it, and breathe out naturally before reading the measurement. Where you place the tape affects the result more than most people expect, so measuring the same spot the same way each time matters more than any single reading.

Worth knowing: this is a screening tool, not a diagnosis — it's meant to inform a conversation with a doctor or dietitian, not replace one. NICE's classification bands here are specifically for adults; children and young people are assessed under a separate NICE recommendation with age-specific context, so this calculator (like our other calculators) is built for adult use. The ratio also assumes a fairly stable standing height and a waist measurement that reflects body composition rather than something else changing it — it isn't designed for use during pregnancy, or for anyone whose height has been significantly altered by a spinal or growth-related condition, since the underlying assumption (waist tracks fat, height is stable) doesn't hold as well in those cases.

Primary evidence: Ashwell, M., Gunn, P., & Gibson, S. (2012). Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis. Obesity Reviews, 13(3), 275–286. A meta-analysis of 31 studies and more than 300,000 adults found WHtR discriminated cardiometabolic risk factors (diabetes, hypertension, cardiovascular disease) 4–5% better than BMI, and better than waist circumference alone.

Read the meta-analysis →

Guideline: National Institute for Health and Care Excellence (2025). NG246: Overweight and obesity management. Recommendations 1.9.14–1.9.15.

Read the NICE guideline →

Recent supporting study: Mendes, T.B., Bittencourt, M.S., et al. (2025). Waist-to-height ratio and coronary artery calcium incidence: the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). The Lancet Regional Health – Americas. Following 2,721 adults with no cardiovascular disease at baseline for over 5 years, WHtR remained a significant predictor of new coronary artery calcium after adjusting for standard risk factors (age, sex, smoking, exercise, diabetes, hypertension, cholesterol) — BMI and waist circumference alone did not.

Read the study →