Article # 364. How to Estimate Lean Body Mass

How to Estimate Lean Body Mass

Your lean body mass is your body weight that doesn't come from fat. This includes your muscle weight in addition to water weight, bone and other non-fat tissue. You'll commonly use your lean body mass to gauge your general level of fitness. Lean body mass is a better measure of fitness than total body weight because it takes body composition into account. You can calculate your lean body mass from your weight and physical measurements that depend on your gender.

Step 1

Weigh yourself in pounds and record your weight. You should check your weight when you first wake up so that your water weight will be at its lowest level.

Step 2

Measure your waist in inches at the navel with the tape measure.

Step 3

Take additional measurements in inches if you're female. Obtain your wrist measurement at its fullest point, your forearm at its fullest point and your hip measurement at its fullest point.

Step 4

Calculate your lean body mass if you're female. This is given by the equation (body weight x 0.732) - (waist measurement x 0.157) + (wrist measurement / 3.14) + (forearm measurement x 0.434) -- (hip measurement x 0.249) + 8.987. Assume you weigh 134 pounds, have a 29-inch waist, a 6-inch wrist, 8-inch forearm and 37-inch hips. Your lean body mass is (134 x 0.732) - (29 x 0.157) + (6 / 3.14) + (8 x 0.434) -- (37 x 0.249) + 8.987 = 99 pounds.

Step 5

Compute your lean body mass if you're male. This is given by the equation (body weight x 1.082) -- (4.15 x waist measurement) + 94.42. Assume that you weigh 155 pounds and have a 33-inch waist. Your lean body mass is (155 x 1.082) + 94.42 -- (4.15 x 33) = 125 pounds.

Things You'll Need

• Scale
• Tape measure
• Calculator