Question
What is lean body mass?
Lean body mass is the portion of total body weight that is not fat mass. It includes muscle, bone, water, organs, and other non-fat tissue.
Fitness
Use OmniCalc's lean body mass calculator to estimate lean body mass, lean-mass percentage, and simple fat-mass context from your height and weight.
Lean body mass calculator
Use your sex, height, and weight to estimate lean body mass for planning nutrition, training, and progress benchmarks.
Why this result matters
Fast lean-mass estimates for planning nutrition and physique goals. Use the tool above to enter a few clear inputs and get a practical answer you can use right away.
This lean body mass calculator helps people estimate how much of their body weight is likely lean mass instead of fat mass. It is useful for physique tracking, protein planning, and understanding body composition beyond total scale weight.
Formula and method
This calculator uses a standard formula-based lean body mass estimate derived from sex, height, and body weight. It is not a clinical measurement, but it is useful for quick planning and body-composition context.
Example
If you are trying to understand how much of your weight may be lean mass, this calculator gives you a fast estimate you can use alongside body fat, protein, and calorie planning tools.
FAQ
Short answers to the questions people often ask before or after using the tool.
Question
Lean body mass is the portion of total body weight that is not fat mass. It includes muscle, bone, water, organs, and other non-fat tissue.
Question
No. Muscle is part of lean body mass, but lean body mass also includes water, bone, organs, and other non-fat tissue.
Question
It can help add context for protein intake, physique goals, and weight changes, especially when the scale alone does not tell the full story.
Related calculators
If the next question is close to this one, these are the best pages to open next.
Fitness
Use OmniCalc's body fat calculator to estimate body fat percentage, fat mass, and lean mass from practical body measurements.
Fitness
Use OmniCalc's protein calculator to estimate daily protein intake for general health, muscle gain, fat loss, or endurance training.
Fitness
Use OmniCalc's TDEE calculator to estimate maintenance calories and practical cut or bulk targets from your size, age, and activity level.
Fitness
Use OmniCalc's ideal weight calculator to estimate a reference target based on height and sex, then compare it with a broader healthy weight range.