Body Fat Calculator
Estimate your body fat percentage in your browser with the U.S. Navy circumference method or the BMI method. No photo, no upload, no login.
Fitness range by the American Council on Exercise categories.
Fat mass 14.3 kg (31.5 lb) · Lean mass 67.3 kg (148.5 lb)
How this calculator works
Two established methods are offered. Both are approximations built on population data, so treat the number as a range signal rather than an exact value.
U.S. Navy circumference method
Uses measured circumferences (neck and waist, plus hip for women) together with height. The equations were developed by Hodgdon and Beckett at the Naval Health Research Center in 1984 and are documented in the U.S. Navy Physical Readiness Program. It is the more common at-home estimate because it needs only a tape measure.
BMI method
Derives body fat from BMI together with age and sex. It needs only height, weight, and age, but it is less precise because BMI does not separate muscle from fat. Use it as a quick cross-check rather than a primary figure.
Body fat category ranges
Categories follow the American Council on Exercise (ACE) adult reference ranges. Your result is placed into the matching band.
Men
Women
How accurate is a body fat calculator?
Calculators give an estimate, not a measurement. The U.S. Navy and BMI methods are based on population averages, so results vary by person. Clinics use DEXA, hydrostatic weighing, or air-displacement plethysmography when a precise figure is needed.
Not medical advice. This tool gives an estimate based on published formulas, not a clinical measurement. Body composition varies by individual. If you have health concerns, talk to a qualified healthcare professional. See our disclaimer.
Related body composition tools
Estimate body fat from a photo, calculate fat-free mass index, work out daily energy expenditure, or review the body fat percentage chart.