Lean Body Mass Calculator: method, checked example and practical limits
Estimate adult lean body mass with the sex-specific Boer height-and-weight equations. Estimated lean mass is a prediction from body measurements rather than a direct body-composition test.
Inputs used by this calculator
Lean Body Mass Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Equation sex | Female equation | Female equation · Male equation | Supplies the equation sex quantity used by the published equation or result breakdown. |
| Height (cm) | 165 | 100 to 250 | Supplies the height (cm) quantity used by the published equation or result breakdown. |
| Weight (kg) | 70 | 20 to 400 | Supplies the weight (kg) quantity used by the published equation or result breakdown. |
Inputs and measurement conventions
The quantities used on this page are Equation sex, Height (cm), Weight (kg). Start with values for the same situation and read the units attached to each field. The field reference below shows supported choices and numerical limits.
Fat-free mass and muscle mass are not identical. Edema, pregnancy and unusual body composition can undermine equation-based estimates.
Method and equation
Apply the adult Boer anthropometric equation to height in centimeters, mass in kilograms and the selected sex coefficient.
Lean Body Mass Calculator uses the following stated relationship: male LBM=0.407W+0.267H−19.2; female LBM=0.252W+0.473H−48.3. Its assumptions determine which question the answer can resolve.
male LBM=0.407W+0.267H−19.2; female LBM=0.252W+0.473H−48.3Worked calculation with the starting values
Equation sex: Female equation; Height (cm): 165; Weight (kg): 70. These starting values give 47.385 kg estimated lean body mass. The calculation breakdown is Lean fraction: 67.69285714285715%; Estimated fat mass: 22.615; Equation: female.
A 165 cm, 70 kg adult using the female equation has an estimated lean mass near 47.4 kg.
Reading the answer
Estimated lean mass is a prediction from body measurements rather than a direct body-composition test.
Lean fraction: 67.69285714285715%; Estimated fat mass: 22.615; Equation: female. These intermediate quantities make the stated Lean Body Mass Calculator model inspectable; they should be read together with the main answer rather than treated as independent guarantees.
Common errors and model boundaries
Fat-free mass and muscle mass are not identical. Edema, pregnancy and unusual body composition can undermine equation-based estimates.
This anthropometric estimate is not a direct body-composition measurement and may be inaccurate outside the studied adult ranges.
Independent verification and next decision
No. Lean mass includes water, organs, bone and other nonfat tissues as well as muscle.
For the Lean Body Mass Calculator method, compare male LBM=0.407W+0.267H−19.2; female LBM=0.252W+0.473H−48.3 with the starting inputs and the calculation table. The linked Boer: estimated lean body mass in adult fluid-volume normalization and CDC: BMI and body-composition limitations references identify the relevant definitions, conventions or domain limitations. Retain intermediate precision when comparing a manually worked answer.
Lean Body Mass Calculator worked-example ledger
| Quantity | Example value | Role |
|---|---|---|
| Equation sex | Female equation | Entered assumption |
| Height (cm) | 165 | Entered assumption |
| Weight (kg) | 70 | Entered assumption |
| Main answer | 47.385 kg estimated lean body mass | Calculated from the starting inputs |
| Lean fraction | 67.69285714285715% | Intermediate or contextual output |
| Estimated fat mass | 22.615 | Intermediate or contextual output |
| Equation | female | Intermediate or contextual output |
Frequently asked questions
Can I use the result as measured muscle weight?
No. Lean mass includes water, organs, bone and other nonfat tissues as well as muscle.
Which relationship does the Lean Body Mass Calculator use?
Apply the adult Boer anthropometric equation to height in centimeters, mass in kilograms and the selected sex coefficient. The displayed relationship is male LBM=0.407W+0.267H−19.2; female LBM=0.252W+0.473H−48.3.
What do the starting values produce in the Lean Body Mass Calculator?
Equation sex: Female equation; Height (cm): 165; Weight (kg): 70. These starting values give 47.385 kg estimated lean body mass. The calculation breakdown is Lean fraction: 67.69285714285715%; Estimated fat mass: 22.615; Equation: female.
How should I interpret this Lean Body Mass Calculator answer?
Estimated lean mass is a prediction from body measurements rather than a direct body-composition test.
Which input mistake most affects the Lean Body Mass Calculator?
Fat-free mass and muscle mass are not identical. Edema, pregnancy and unusual body composition can undermine equation-based estimates.
What is outside this Lean Body Mass Calculator model?
This anthropometric estimate is not a direct body-composition measurement and may be inaccurate outside the studied adult ranges.
What to keep in mind
This anthropometric estimate is not a direct body-composition measurement and may be inaccurate outside the studied adult ranges.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.