Body fat calculator.
Six methods with published equations.
Choose a method, then enter your measurements.
Calliper folds use millimetres, tape measurements use centimetres.
Where the equations come from.
Each method here is implemented from its published source.
Jackson/Pollock, 7 sites
Chest, midaxillary, tricep, subscapular, abdominal, suprailiac and thigh, with age. The full protocol from Jackson & Pollock (1978, men) and Jackson, Pollock & Ward (1980, women), validated against hydrostatic weighing. It uses the most information of the calliper methods here.
Jackson/Pollock, 3 sites
The short form of the same work. The published protocols measure men at chest, abdominal and thigh, and women at tricep, suprailiac and thigh, so the form swaps sites with the selected sex.
Jackson/Pollock, 4 sites
Abdominal, thigh, tricep and suprailiac, with age — the 1985 generalised equations, which give a percentage directly rather than passing through body density.
Parrillo, 9 sites
All nine folds, multiplied by 27 and divided by body weight in pounds; the form takes kilograms and converts. From John Parrillo's bodybuilding practice rather than a validated regression, and carried here because coaches still use it and long client records depend on it.
Durnin/Womersley, 4 sites
Bicep, tricep, subscapular and suprailiac. Durnin & Womersley's 1974 regressions, with coefficients selected by sex and age band — the standard clinical skinfold method for decades.
Navy tape measure
No callipers: height, neck and abdomen girths, plus hip for women, from Hodgdon & Beckett's 1984 work for the US Navy. It needs nothing but a tape measure and it is the least precise method here. The female equation cannot be computed without the hip girth, which is why the field appears.
Each method is an estimate only.
Skinfold equations typically land within 3–4
percentage points of the
gold-standard methods such as hydrostatic weighing or DEXA.
The number that matters is the trend under one method, one
measurer, and consistent conditions.
For females, please be aware that your hormonal cycle can heavily skew results, and I advise delaying measurements until after your period week.
Sources: Jackson & Pollock, Br J Nutr 40 (1978) 497–504 · Jackson, Pollock & Ward, Med Sci Sports Exerc 12 (1980) 175–181 · Jackson & Pollock, Phys Sportsmed 13 (1985) 76–90 · Durnin & Womersley, Br J Nutr 32 (1974) 77–97 · Hodgdon & Beckett, Naval Health Research Center reports 84-11 and 84-29 (1984) · Parrillo & Greenwood-Robinson, High-Performance Bodybuilding (1993) · Siri, in Techniques for Measuring Body Composition (1961).
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