Calculate your BMI to monitor your fitness/weightloss goals.

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 but will be extremely close. 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



Body Fat Percentage Categories


Classification                Women (% fat)           Men (% fat)

Essential Fat                       10-12%                          2-4%

Athletes                              14-20%                         6-13%

Fitness                                21-24%                        14-17%

Acceptable                         25-31%                        18-25%

Obese                                   32%+                           25%+