Lean body mass is everything in your body that is not fat, including muscle, bone, organs, and water. This calculator gives you two ways to estimate it. If you know your body fat percentage, it simply removes that fraction from your weight to give lean mass and fat mass directly. If you do not, it applies the Boer formula, which estimates lean mass from height, weight, and sex, and is widely used in clinical settings. Enter weight in kilograms and height in centimetres, pick your sex, and optionally add a body fat percentage to switch methods. Both results are shown so you can compare them. Everything is calculated locally in your browser. These are estimates for general information only, not clinical measurements or medical advice, so treat them as a rough guide rather than a precise body composition reading.
If you provide a body fat percentage it subtracts the fat mass from your weight, and otherwise it uses the Boer formula based on weight, height and sex.
Lean mass is everything that is not fat, including muscle, bone and organs, while fat mass is your weight times your body fat percentage.
Use the Boer option when you do not have a measured body fat percentage, since it estimates lean mass from weight and height instead.
Lean body mass is everything in your body that is not fat, including muscle, bone, organs, and water. This calculator gives you two ways to estimate it.
Yes. Lean Body Mass Calculator is completely free, with no sign-up and no usage limits.
Yes. Lean Body Mass Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Lean Body Mass Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.