Lean Body Mass Calculator

What is lean body mass?

Lean body mass is the total weight of your body if you had no body fat. It includes the weight of your organs, bones, muscles, blood and skin. Basically if you subtract the weight that comes from fat from your total weight you get your lean body mass.

It is especially important to know your muscle mass if you are trying to lose weight. By looking at your lean body mass, you can monitor how much muscle you are losing.

Knowing how to calculate your muscle mass will also help you decide how much fat you should lose and what your body fat percentage will be after that.
Knowing this can help those who want to lose weight to maintain their weight loss from fat alone. If you can keep your lean body mass stable while lowering your overall weight, you'll know you're only losing fat - not muscle or bone density, which is often the case.

How to measure circumference

To calculate body fat percentage using the U.S. Navy method, the circumference of both the neck and waist is required for men; women also need to enter the circumference of the hips.

Measure the waist horizontally around the belly button for men, women measure at their leanest point. To get a reliable result, the stomach should not be pulled inwards.

Measure the neck circumference at a point just below the larynx. Look straight ahead. Keep the tape measure as close to horizontal as anatomically possible.

For women, measure the hip horizontally at the widest point.