Body Composition Calculators
Calculate army body fat, BMI prime and body fat and other body composition calculations.
All Body Composition Calculators
Body Composition Guides
BMI vs Body Fat Percentage: Which Is a Better Health Indicator?
BMI is a quick screening tool based only on height and weight — it can't tell muscle from fat, so a muscular, athletic person can register as "overweight" or "obese" despite having very little body fat. Body fat percentage measures composition directly and is the more accurate indicator for an individual, but BMI remains useful as a fast, no-measurement population-level screen.
Read guideHow Body Surface Area Is Calculated From Weight and Height
Body surface area comes from the century-old Du Bois formula — weight and height each raised to their own fractional power and multiplied together — still the standard estimate behind clinical medication dosing today.
Read guideHow Your Healthy Weight Range Is Calculated
A healthy weight range comes from inverting the BMI formula at the WHO's normal-BMI cutoffs (18.5 and 25), giving a low and high weight for any given height rather than a single target number.
Read guideHow Your Ideal Weight Is Estimated by Four Classic Formulas
Four decades-old clinical formulas — Devine, Robinson, Miller, and Hamwi — each estimate ideal bodyweight from height and sex using their own base weight and slope, and averaging all four gives a single reference point.
Read guideWaist-to-Height vs Waist-to-Hip Ratio: What Do They Actually Measure?
Both ratios flag abdominal fat as a cardiovascular risk factor, but they use different reference points and thresholds — waist-to-height ratio compares your waist to your own height (keep it under 0.5), while waist-to-hip ratio compares waist to hip circumference with different, sex-specific cutoffs — and both can flag risk even when BMI looks normal.
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