Body Fat Formula
If you are unable to use our body fat calculator, or if you are interested in how your body fat percentage is calculated, this page has the mathematical body fat formula.
The best time to use this formula, is in the morning. Your body weight and waist measurements are the most accurate just after you wake up from 7-8 hours of sleep.
The formula below will not calculate your exact body fat percentage. The most accurate way is underwater weighing, but this formula should give you a consistent measurement you can use as a guideline so you can determine if you're losing body fat and/or muscle.
Body Fat Formula for Women
Factor 1 = (Total body weight x 0.732) + 8.987
Factor 2 = Wrist measurement (at fullest point) / 3.140
Factor 3 = Waist measurement (at naval) x 0.157
Factor 4 = Hip measurement (at fullest point) x 0.249
Factor 5 = Forearm measurement (at fullest point) x 0.434
Lean Body Mass = Factor 1 + Factor 2 - Factor 3 - Factor 4 + Factor 5
Body Fat Weight = Total bodyweight - Lean Body Mass
Body Fat Percentage = (Body Fat Weight x 100) / total bodyweight
Body Fat Formula for Men
Factor 1 = (Total body weight x 1.082) + 94.42
Factor 2 = Waist measurement x 4.15
Lean Body Mass = Factor 1 - Factor 2
Body Fat Weight = Total bodyweight - Lean Body Mass
Body Fat Percentage = (Body Fat Weight x 100) / total bodyweight