Lean Body Mass Calculator

Lean Body Mass is evaluated from Sex, Weight and Height. The calculation reports Boer Formula, James Formula and Hume Formula.

Results

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About the Lean Body Mass Calculator

Lean Body Mass is treated here as a quantitative relation between Sex, Weight and Height and Boer Formula, James Formula, Hume Formula and Average LBM.

The calculator uses a multi formula configuration. Each reported value is read as a direct evaluation of the stored rules with the declared field formats and units.

Formula basis:
Boer: Men = 0.407W + 0.267H - 19.2; Women = 0.252W + 0.473H - 48.3
James: Men = 1.1W - 128(W/H)^2; Women = 1.07W - 148(W/H)^2
Hume: Men = 0.3281W + 0.33929H - 29.5336; Women = 0.29569W + 0.41813H - 43.2933
W = weight in kg, H = height in cm

Interpret the outputs in the order shown by the result fields. Optional inputs affect only the outputs that depend on those variables.

Formula & How It Works

The calculation applies the following relations exactly as recorded in the metadata:

Boer: Men = 0.407W + 0.267H - 19.2; Women = 0.252W + 0.473H - 48.3
James: Men = 1.1W - 128(W/H)^2; Women = 1.07W - 148(W/H)^2
Hume: Men = 0.3281W + 0.33929H - 29.5336; Women = 0.29569W + 0.41813H - 43.2933
W = weight in kg, H = height in cm

Each output field is produced by substituting the supplied inputs into the relevant relation and then applying the declared rounding or text format.

Worked Examples

Example 1: Athletic Male, 80 kg, 180 cm

Inputs

sex: male weight_kg: 80 height_cm: 180
Boer Formula: 61.4 kg. James Formula: 62.7 kg. Hume Formula: 57.8 kg. Average LBM: 60.6 kg. Estimated Fat Mass*: 19.4 kg

With Sex = male, Weight = 80 and Height = 180 as the stated inputs, the result is Boer Formula = 61.4 kg, James Formula = 62.7 kg and Hume Formula = 57.8 kg. Each value corresponds to the declared output fields.

Example 2: Active Female, 62 kg, 165 cm

Inputs

sex: female weight_kg: 62 height_cm: 165
Boer Formula: 45.4 kg. James Formula: 45.4 kg. Hume Formula: 44 kg. Average LBM: 44.9 kg. Estimated Fat Mass*: 17.1 kg

With Sex = female, Weight = 62 and Height = 165 as the stated inputs, the result is Boer Formula = 45.4 kg, James Formula = 45.4 kg and Hume Formula = 44 kg. Each value corresponds to the declared output fields.

Example 3: Overweight Male, 110 kg, 175 cm

Inputs

sex: male weight_kg: 110 height_cm: 175
Boer Formula: 72.3 kg. James Formula: 70.4 kg. Hume Formula: 65.9 kg. Average LBM: 69.6 kg. Estimated Fat Mass*: 40.4 kg

With Sex = male, Weight = 110 and Height = 175 as the stated inputs, the result is Boer Formula = 72.3 kg, James Formula = 70.4 kg and Hume Formula = 65.9 kg. Each value corresponds to the declared output fields.

Example 4: Lean Female Athlete, 55 kg, 168 cm

Inputs

sex: female weight_kg: 55 height_cm: 168
Boer Formula: 45 kg. James Formula: 43 kg. Hume Formula: 43.2 kg. Average LBM: 43.7 kg. Estimated Fat Mass*: 11.3 kg

With Sex = female, Weight = 55 and Height = 168 as the stated inputs, the result is Boer Formula = 45 kg, James Formula = 43 kg and Hume Formula = 43.2 kg. Each value corresponds to the declared output fields.

Common Use Cases

  • Calculate protein targets based on lean body mass
  • Estimate drug dosing adjusted for lean mass
  • Track lean mass changes during a recomposition program
  • Understand how much of your weight is lean vs fat