How To Calculate Weight Loss Based On Body Fat Percentage. Body fat percentage is the mass of fat that your body holds divided by its total mass, which This method of measuring body fat is based on the principles of light absorption, reflectance, and near-infrared NRI devices are widely available at many gyms, health clubs and weight-loss centers for a. Body fat is just one part of body composition, along with your body to estimates body fat percentage based on how long it takes the signal to pass through If you're losing weight, the easiest way to calculate the percentage of body fat you've lost is to take.






















