Your body fat percentage is the percentage of your weight that comes from fat. Skin-fold calipers are a common method of measuring body fat percentage, but you may not have access to calipers. You can also measure body fat percentage with a scale and tape measure. This method uses a different set of measurements for men and women, since the distribution of fat is different between the genders.
Take body measurements in inches with a tape measure. Everyone must measure their waist at the navel. You must also measure your hips, forearm and wrist if you’re female. Measure your hips and forearm at their fullest point. Measure your wrist at the thinnest point.
Weigh yourself in pounds with a scale. Do this when you wake up so that your weight will be at its lowest level of the day.
Derive your lean body weight if you’re male. Your lean body weight is equal to (1.082 x total weight) - (4.15 x waist measurement) + 94.42. In this example, your total weight is 155 pounds and your waist measurement is 35 inches. You have a lean body weight of (1.082 x 155) – (4.15 x 35) + 94.42 = 117 pounds.
Compute your lean body weight if you’re female. Your lean body weight is equal to (0.732 x total weight) - (0.157 x waist measurement) – (0.249 x hip measurement) + (0.434 x forearm measurement) + (wrist measurement / 3.14) + 8.987. In this example, you weigh 143 pounds and have a waist measurement of 28 inches. Your hip measurement is 39 inches, your forearm measurement is 10 inches, and your wrist measurement is 6.5 inches. You have a lean body weight of (0.732 x 143) - (0.157 x 28) – (0.249 x 39) + (0.434 x 10) + (6.5 / 3.14) + 8.987 = 106 pounds.
Convert your lean body mass to your body fat percentage. Your body fat percentage is equal to (body weight - lean body mass) / (body weight) x 100. Using the previous example for a man, you weigh 155 pounds and have a lean body mass of 116 pounds Your body fat percentage is (155 - 116) / 155 x 100 = 25.2 percent.