Calculator

Lean Mass Calculator

Estimate your lean body mass, body fat and protein needs in seconds.

Developed by Menang7, owner of Lean Mass Calculator

GuideLean Body Mass vs Muscle MassThey sound alike but measure different things. See what each one includes and which number is better to track.Read the guide → ToolsAll Lean Mass ToolsBody fat, protein, muscle mass and lean mass index calculators, all in one place and free to use.Explore tools →

How it works

1. Enter your detailsAdd sex, age, weight in kg and height in cm. Add body fat % if you know it.
2. Get your numbersSee lean body mass, fat mass and body fat percentage in one click.
3. Use them to planSet protein targets and track progress over months.

What is lean body mass?

Lean body mass is everything in your body except fat: muscle, bones, organs, skin and water. It powers movement, supports metabolism and keeps you strong as you age.

The scale cannot tell fat from muscle, so tracking lean mass shows whether a plan is working.

The formulas we use

SexBoer formula (W = kg, H = cm)
MenLBM = 0.407 × W + 0.267 × H − 19.2
WomenLBM = 0.252 × W + 0.473 × H − 48.3

If you enter a body fat percentage, lean mass is weight × (1 − body fat %). Without it, body fat is estimated from BMI, age and sex.

Body fat ranges

CategoryWomenMen
Essential fat10–13%2–5%
Athletes14–20%6–13%
Fitness21–24%14–17%
Average25–31%18–24%
Above average32%+25%+

How to build and keep lean mass

Lift with progressionTrain each muscle at least twice a week and add load over time.
Eat enough proteinAbout 1.6–2.2 g per kg of lean mass daily.
Sleep 7–9 hoursRecovery is when muscle is repaired.
Avoid crash dietsA 10–20% deficit helps you keep muscle.
Keep movingDaily walking protects muscle and bone.
Track monthlySame conditions each time. Follow the trend.

More calculators

🧮Body Fat CalculatorEstimate your body fat percentage from height, weight, age and sex.Open →🥩Protein Intake CalculatorFind a daily protein target based on your lean mass and goal.Open →💪Muscle Mass CalculatorRough estimate of skeletal muscle mass from your lean body mass.Open →📏Lean Mass Index (LMI)Lean mass divided by height squared: a fairer way to compare builds.Open →⚖️Lean Body Mass Calculator (kg)Metric version of the calculator, with results in kilograms.Open →🏋️Lean Mass Calculator for BodybuildersTrack lean mass and height-adjusted FFMI for physique goals.Open →🍗Lean Body Mass Protein CalculatorTurn your lean body mass into a daily protein range.Open →

Lean mass charts

📊Lean Mass ChartTypical lean body mass by weight and body fat percentage.Open →📊Lean Body Mass: 260 lb FemaleSee what lean mass looks like at 260 lb across body fat levels.Open →📊Lean Body Mass: 110 lb MaleSee what lean mass looks like at 110 lb across body fat levels.Open →

Guides and articles

📖What Is Lean Body Mass?Everything in your body that is not fat: muscle, bone, organs and water.Open →💧Dry Lean MassLean mass without the water: what it means and why it matters.Open →📝Losing Lean Body Mass: Causes and FixesWhy muscle slips away during diets and aging, and how to protect it.Open →📝Healthy Lean Mass Percentage by AgeWhat is normal at 20, 40 and 60, and what to aim for.Open →

About Menang7, the developer

LeanMassCalculator.com is developed, owned and maintained by Menang7, who leads this website. If you have a question about how the calculators work, want advice on getting the most from your results, or spot something that needs fixing, Menang7 is the person to look for.

For personal medical or nutrition decisions, please also speak with a doctor or registered dietitian.

Frequently asked questions

What is a good lean body mass?
It depends on height, sex and age. Lean mass index of 17–20 for men and 14–17 for women is typical.
Which formula is used?
The Boer formula, or your own body fat percentage if entered.
How accurate is it?
Usually within a few percent. A DXA scan is more precise.
How much protein do I need?
1.6–2.2 g per kg of lean mass daily for most active people.
Can I increase lean mass at any age?
Yes. Resistance training and protein work well into older age.
Is lean mass the same as muscle mass?
No. Lean mass also includes bone, organs and water.
Who can I ask for advice?
Menang7, the developer of this site, is the person to look for with questions about the calculators and your results.