The WeighTrainer

Circumference Bodyfat / Lean Body Mass Calculator

The following calculator gives you an estimate of your % bodyfat and lean body mass based on your weight, height, age and simple tape measurements (i.e. anthropometric measurements). Skin-fold measurements alone tend to underestimate body fat percentage in the obese [1] and very lean (particularly with low hydration levels). The following calculator is based on equations [2, 3] which are useful for people in these groups as well as people with loose skin after very large weight loses. It is generally accurate to within a few percent. Anecdotally, it has also proven to be reasonably accurate with drug-free, genetically typical bodybuilders.



  • Age – your age in years
  • Height – your height without shoes
  • Waist size – measure around your waist at your navel and also at the point midway between your navel and the bottom of your sternum, and take the average of these two measurements - that is your "Waist" measurement. Stand tall, but do not deliberately suck in your stomach or the estimation will be wrong.
  • Iliac – measure around where your upper pelvic bones protrude the most (you can feel for them on either side of your waist/hips)
  • Hips – measure around the hips at the maximum protrusion of the buttocks
gender Male Female
Your age years
Your weight pounds kilos
Your height inches cm
Your waist inches cm
Your iliac inches cm
Your hips inches cm

  1. Ada L. Garcia, Karen Wagner, Torsten Hothorn, Corinna Koebnick, Hans-Joachim F. Zunft, and Ulrike Trippo, "Improved Prediction of Body Fat by Measuring Skinfold Thickness, Circumferences, and Bone Breadths", Obesity Research, Vol. 13, No. 3, March 2005, pp. 626-634.
  2. Tran Z.V. and Weltman A., "Predicting body composition of men from girth measurements", Hum Biol. Vol. 60, Feb. 1988, pp. 167-175.
  3. Tran Z.V. and Weltman A., "Generalized equation for predicting body density of women from girth measurements", Med Sci Sports Exerc. Vol. 21, Feb. 1989, pp. 101-104.


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