Lean Body Mass
58.0 kg
Fat Mass (est.)
17.0 kg
Method
Boer
Body & Fitness
Lean Body Mass Calculator
Estimate lean body mass (LBM) using height, weight, and sex-based formulas.
By Calculator Suite Pro Editorial Team | Last updated March 18, 2026
Use this estimate as body-metric context, then compare nearby fitness tools when one number needs more perspective.
Explore the Body & Fitness group for nearby calculators, examples, and guide links.
About this calculator
Lean body mass (LBM) estimates how much of your body weight is not fat. It includes muscle, bone, organs, and water. LBM can be helpful for understanding body composition trends.
This calculator uses common height- and sex-based formulas to estimate LBM from weight and height. It is an estimate, not a lab measurement.
If you also estimate body fat percentage, you can compare the two views and track progress more clearly than weight alone.
How the estimate is calculated
A short explanation of how the body or training inputs are turned into an estimate.
- LBM is estimated from weight and height using sex-specific coefficients.
- We compute lean mass (kg) and you can infer fat mass as total weight minus lean mass (rough estimate).
- Because it is formula-based, accuracy varies by individual.
- Use it as a trend tool rather than an absolute truth.
Formula and interpretation limits
These are the formulas, assumptions, and screening limits used by this body or fitness calculator.
- LBM is estimated from weight and height using sex-specific coefficients.
- Because it is formula-based, accuracy varies by individual.
Where this estimate can help
Use these scenarios to decide whether the output is useful for tracking, planning, or a basic screen.
- Tracking recomposition (muscle gain vs fat loss)
- Setting strength and fitness goals
- Understanding weight changes (lean vs fat trend)
- Nutrition planning context (protein targets)
- Comparing progress beyond BMI
- Fitness coaching check-ins
- Estimating lean mass for training planning
- Trend tracking across months
How to enter body metrics
- Select sex.
- Enter weight and height.
- Calculate to see estimated LBM (kg).
- Compare with total weight to understand fat mass trends.
- Track changes over time under similar conditions.
Body-metric mistakes to avoid
Confusing results usually come from measurement errors, formula assumptions, or over-interpreting a single number.
- Treating LBM estimate as exact muscle mass (LBM includes more than muscle).
- Entering height/weight in the wrong units.
- Comparing results across different formulas without context.
- Focusing on a single reading instead of trend over time.
- Using it for medical decisions without professional guidance.
Interpretation tips
- Use LBM trends along with body fat percentage for a fuller picture.
- If you are strength training, focus on performance and measurements, not only formulas.
- For calorie targets, use TDEE and adjust based on weekly progress.
- Measure under consistent conditions for the most useful trend tracking.
Glossary
Quick definitions for body and fitness terms used on this page.
LBM
Lean Body Mass: the non-fat portion of body weight.
Fat mass
The portion of body weight that is fat tissue (estimated, not measured here).
Body-metric examples
Example
Input: Sex: Men, Weight: 80kg, Height: 180cm
Output: LBM estimate shown (kg)
Example
Input: Sex: Women, Weight: 60kg, Height: 165cm
Output: LBM estimate shown (kg)
Recomposition
Input: Weight stable, LBM estimate increases
Output: Potential positive trend (estimate)
Body and fitness guides
Related explainers that add context around formulas, trends, and interpretation limits.
Free Macro Calculator for Cutting, Maintenance, and Bulking
Set calorie targets and macro split ranges for fat loss, maintenance, or muscle gain without guesswork.
Understanding the Impact of BMI on Cancer Risk: What the Latest Research Shows
A practical guide to how BMI relates to cancer risk, why weight matters biologically, and how to use that information without treating BMI as a verdict.
FAQ
Is lean body mass the same as muscle mass?
No. Lean body mass includes muscle plus bone, organs, and water. It is broader than muscle mass.
How accurate is LBM from formulas?
It varies by individual. Use it mainly to track trends rather than exact numbers.
Can I estimate fat mass from LBM?
Roughly: fat mass = total weight - LBM. But both values are estimates, so treat it as directional.
Should I use this for medical dosing?
No. Use professionally validated methods and consult clinicians for dosing decisions.
Does sex matter?
Yes. The formulas use sex-specific coefficients.
Can athletes use this?
Yes as a trend estimate, but athletes can differ more from formula assumptions.
Body-metric references and update notes
Last updated: March 18, 2026
Reviewed by Calculator Suite Pro Editorial Team.
Use the output for general context; clinical or high-stakes decisions need professional confirmation.
Related body and fitness calculators
Use nearby body-metric tools together when one estimate needs more context.
BMI Calculator
Calculate BMI (Body Mass Index) and view the category range.
Body Fat Percentage Calculator
Estimate body fat percentage using measurement-based formulas (US Navy method).
BMR Calculator
Calculate Basal Metabolic Rate (BMR) using the Mifflin-St Jeor formula.
TDEE Calculator
Estimate daily calorie needs (TDEE) based on BMR and activity level.
Waist-to-Hip Ratio (WHR) Calculator
Calculate waist-to-hip ratio to assess fat distribution.
Ideal Body Weight Calculator
Estimate ideal body weight using common clinical formulas (Devine and others).