Fat distribution calculators
Where fat sits matters more than how much you weigh. Waist-based ratios and shape indices capture visceral fat (the kind that drives cardiometabolic risk) with a tape measure and thirty seconds.
5 calculators
Waist Circumference Calculator
Check your waist against the WHO action levels of 94 and 102 cm for men and 80 and 88 cm for women, plus the IDF population lines and waist-to-height ratio.
Body Roundness Index (BRI) Calculator
Work out your Body Roundness Index from height and waist, read it against the NHANES mortality quintiles, and see it beside ABSI, conicity and BAI.
Waist-to-Height Ratio Calculator
Check your waist-to-height ratio against the evidence-backed bands. Keep your waist under half your height, a better risk screen than BMI alone.
Waist-to-Hip Ratio Calculator
Calculate your waist-to-hip ratio against the WHO risk thresholds of 0.90 for men and 0.85 for women, with the waist circumference cut-offs alongside.
Visceral Fat Calculator
A tape proxy for central fat: waist-to-height 0.5, WHO 94/102 and 80/88 cm lines, and body roundness index. Not a VAT volume scan. Use the WHO waist point.
Guides that explain these numbers
- BMI, explained properly
- Why BMI is wrong for athletes
- Asian BMI cut-offs, explained without the muddle
- What changed in the 2025 obesity definition
- How to measure your waist accurately
- How to track body composition without a DEXA scan
- BMI vs body fat vs waist ratio: which number matters?
Every formula on these pages is written out with its primary source on the methodology page. Results are informational. See the medical disclaimer.