Quick start
- Open the Lean Body Mass Calculator.
- Enter height, weight, and formula sex.
- Use the first example, "Male 180/82: 180 cm, 82 kg", if you want to see a filled-out calculation before entering your own values.
- Calculate, read the formula line, then copy the result only after the units and assumptions look right.
Best uses
Start here if one of these sounds like your job. The examples below show which inputs matter most.
- Estimate lean body mass for fitness context.
- Compare lean mass, implied fat mass, and lean percent from the same inputs.
- Use a formula estimate when body fat percentage is unknown.
- Keep protein, TDEE, and clinical decisions separate from the simple formula output.
What this calculator is for
The Lean Body Mass Calculator estimates fat-free mass with the Boer equation. It is a simple formula reference, not a DEXA scan, body-fat percentage test, muscle-mass scan, protein prescription, or clinical dosing rule.
Use it when you want to: Estimate lean body mass for fitness context. Compare lean mass, implied fat mass, and lean percent from the same inputs.
What to enter
Good answers start with clean inputs. Before calculating, check the labels, units, and dates so the tool is solving the same problem you actually have.
- Enter height, weight, and formula sex.
- Use current values if you want a current formula estimate.
- Use the same formula and the same measurement units when tracking changes.
- Do not enter body fat percentage here; this page is for the height-and-weight Boer equation.
Example walkthrough
Try the calculator example: Male 180/82: 180 cm, 82 kg. The example result is 62.23 kg LBM, 75.9% lean.
- For a male formula input at 180 cm and 82 kg, the Boer equation gives about 62.23 kg of lean body mass. The implied remaining weight is about 19.77 kg, and the lean percent is about 75.9%.
- For a female formula input at 165 cm and 62 kg, the estimate is about 45.37 kg of lean body mass, about 16.63 kg implied fat mass, and about 73.18% lean.
- For a female formula input at 172 cm and 70 kg, the estimate is about 50.70 kg of lean body mass and about 72.42% lean.
Formula and steps
In plain language: The calculator uses Boer lean body mass equations. Male LBM = 0.407 x weight kg + 0.267 x height cm - 19.2. Female LBM = 0.252 x weight kg + 0.473 x height cm - 48.3. Read the result together with the notes on the page, because health and fitness numbers often need personal context.
Read the formula note when you need to understand where the number came from, especially before comparing results over time.
How to read the answer
Read the main estimate first, then read the note beside it. For health, pregnancy, nutrition, kidney, alcohol, or training decisions with real consequences, use qualified professional guidance.
- Lean body mass includes muscle, bone, organs, and water.
- Estimated fat mass is body weight minus the formula lean mass. Lean percent is lean mass divided by body weight.
- The estimate can be useful beside body fat percentage, protein, or TDEE planning, but it is still formula-based and not a personalized plan.
Common mistakes to avoid
Most bad results come from a small input mistake or from using a rough estimate for a decision it cannot safely answer.
- Do not read lean mass as muscle mass only.
- Do not compare formula estimates with DEXA or other methods as if they are identical.
- Do not use it for medication dosing, clinical lean body weight, pediatric formulas, or official body-composition decisions.
- Do not treat it as a protein or TDEE prescription.
What to try next
A related health tool can help check the same topic from another angle, but one number should not replace proper care.
- Use Body Fat Calculator for a tape-based estimate.
- Use BMR Calculator to see how body size affects resting energy estimates.
- Use Protein Calculator or TDEE Calculator only for their separate nutrition estimates, not as replacements for body-composition testing.
Sources and safety notes
This guide uses public-health, clinical, or peer-reviewed references where the calculator needs a specific formula or interpretation boundary.
Source links are provided for transparency, but they do not turn the calculator into medical advice or a replacement for professional care.
Worked examples for Lean Body Mass Calculator
62.23 kg LBM, 75.9% lean
45.37 kg LBM, 73.18% lean
50.70 kg LBM, 72.42% lean
FAQ in plain language
When should I use the Lean Body Mass Calculator?
Use it for simple educational checks, trend tracking, or planning tasks like these: Estimate lean body mass for fitness context. Compare lean mass, implied fat mass, and lean percent from the same inputs. It can help you understand a number, but it cannot explain your whole health situation.
What do the main Lean Body Mass Calculator inputs mean?
Enter formula sex, height in centimeters, and weight in kilograms. The formula sex setting chooses the Boer equation constants. The calculator does not ask for body fat percentage, age, training status, or scan results.
What is the Lean Body Mass Calculator doing with my inputs?
In plain language: The calculator uses Boer lean body mass equations. Male LBM = 0.407 x weight kg + 0.267 x height cm - 19.2. Female LBM = 0.252 x weight kg + 0.473 x height cm - 48.3. Read the result together with the notes on the page, because health and fitness numbers often need personal context.
How should I read the Lean Body Mass Calculator result?
Read lean body mass as a Boer formula estimate of fat-free mass. It includes muscle, bone, organs, and water, so it is not muscle mass only. The estimated fat mass and lean percent are rough comparisons, not a scan or diagnosis.
Does this calculator use body fat percentage?
No. This page estimates lean body mass from height, weight, and formula sex. If you already know body fat percentage, lean body mass can also be estimated as body weight times one minus body fat percentage.
Is lean body mass the same as muscle mass?
No. Lean body mass includes muscle, bone, organs, water, and other fat-free tissue. It is broader than muscle mass, so do not read this as a muscle-only score.
Can I use this for protein or TDEE planning?
You can use the number as rough context, but it is not a protein prescription, fat-loss plan, bodybuilding target, or TDEE rule. Use dedicated nutrition tools and professional guidance when the decision matters.
Related tools
- Body Fat Calculator Estimate body fat percentage with a Navy-style tape method.
- BMR Calculator Estimate resting calories with the Mifflin-St Jeor equation.
- Protein Calculator Estimate protein grams per day from body weight and target factor.
- TDEE Calculator Estimate daily maintenance calories from BMR and activity level.
Keep exploring
If this guide is close but not exact, these links keep you near the same kind of problem.
- Health & Fitness Browse the full category for related tools that help with the same job.
- All free tools Search the complete Access Free Tools library by task, category, or tool name.
- All calculator and utility guides Find more plain-language examples, formulas, mistakes, and result explanations.
- Free calculator resources Start here when you are not sure which calculator page fits.
Privacy and copying results
Recent answers stay visible only while you work in the current browser tab. They are not sent to a server.
Use Copy answer when you want to save the inputs and result in notes, homework, a message, or a project list. Check the units, labels, and limits before copying.