Lean Body Mass

By far, my most visited post is the one concerning “How many calories should I eat to lose weight?“  The questions/comments I get most often concern Lean Body Mass.

Lean Body Mass is simply the portion of your body that is not made up of fat.  It includes your bones, muscle, and other organs.  The easiest way to calculate lean body mass is to multiply your current weight by (1 – Body Fat %).

But that begs the question – how do you calculate you body fat percentage?  There are numerous ways to calculate your body fat percentage, but most of them are expensive, require a trip to an expert, or both.

There is a formula used by the US Navy, however, that is relatively accurate and directionally correct (it moves in the right direction in relative terms).  Though this method is not as accurate as most, it can help you determine the overall direction of your progress and should be withing a few percent of being correct for most people.

The formula takes into account your waist, neck and hips (for women) circumference (distance around), as well as your height.  The measures in the formulas below are in centimeters. 

To convert from inches, simply divide your measures by 0.3937.  Then plug the values into one of the formulas below.

For men, the formula is:

495 / (1.034 – 0.19077 * (LOG (Waist – Neck)) + 0.15456 * (LOG (Height) ) ) – 450

For women, the formula is:

=495 / (1.29579 – 0.35004 * (LOG (Waist + Hip - Neck)) + 0.22100 * (LOG (Height) ) ) – 450

Using these formulas will give you a pretty good estimate of body fat percentage that you can use to calculate both the number of calories you need to lose weight and the number of calories you need to build muscle.