BMR Calculator

BMR is evaluated from Weight, Height and Age. The calculation reports BMR, BMR and BMR.

Results

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About the BMR Calculator

BMR is treated here as a quantitative relation between Weight, Height, Age and Gender and BMR, BMR and BMR.

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

Formula basis:
Mifflin-St Jeor:
Men: BMR = 10W + 6.25H - 5A + 5
Women: BMR = 10W + 6.25H - 5A - 161
Harris-Benedict (revised):
Men: BMR = 13.397W + 4.799H - 5.677A + 88.362
Women: BMR = 9.247W + 3.098H - 4.330A + 447.593
Katch-McArdle (estimated from Mifflin, assumes ~20% body fat):
LBM = W x 0.80
BMR = 370 + 21.6 x LBM
Where W = weight in kg, H = height in cm, A = age in years

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:

Mifflin-St Jeor:
Men: BMR = 10W + 6.25H - 5A + 5
Women: BMR = 10W + 6.25H - 5A - 161
Harris-Benedict (revised):
Men: BMR = 13.397W + 4.799H - 5.677A + 88.362
Women: BMR = 9.247W + 3.098H - 4.330A + 447.593
Katch-McArdle (estimated from Mifflin, assumes ~20% body fat):
LBM = W x 0.80
BMR = 370 + 21.6 x LBM
Where W = weight in kg, H = height in cm, A = age in years

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: Active Young Male

Inputs

weight_kg: 80 height_cm: 180 age: 25 gender: male
BMR: 1,805 kcal/day. BMR: 1,882 kcal/day. BMR: 1,805 kcal/day

With Weight = 80, Height = 180, Age = 25 and Gender = male as the stated inputs, the result is BMR = 1,805 kcal/day, BMR = 1,882 kcal/day and BMR = 1,805 kcal/day. Each value corresponds to the declared output fields.

Example 2: Middle-Aged Woman, Weight Management

Inputs

weight_kg: 68 height_cm: 163 age: 45 gender: female
BMR: 1,313 kcal/day. BMR: 1,387 kcal/day. BMR: 1,313 kcal/day

With Weight = 68, Height = 163, Age = 45 and Gender = female as the stated inputs, the result is BMR = 1,313 kcal/day, BMR = 1,387 kcal/day and BMR = 1,313 kcal/day. Each value corresponds to the declared output fields.

Example 3: Elderly Male, Reduced Metabolism

Inputs

weight_kg: 72 height_cm: 172 age: 70 gender: male
BMR: 1,450 kcal/day. BMR: 1,481 kcal/day. BMR: 1,450 kcal/day

With Weight = 72, Height = 172, Age = 70 and Gender = male as the stated inputs, the result is BMR = 1,450 kcal/day, BMR = 1,481 kcal/day and BMR = 1,450 kcal/day. Each value corresponds to the declared output fields.

Example 4: Overweight Female, Dieting

Inputs

weight_kg: 95 height_cm: 168 age: 38 gender: female
BMR: 1,649 kcal/day. BMR: 1,682 kcal/day. BMR: 1,649 kcal/day

With Weight = 95, Height = 168, Age = 38 and Gender = female as the stated inputs, the result is BMR = 1,649 kcal/day, BMR = 1,682 kcal/day and BMR = 1,649 kcal/day. Each value corresponds to the declared output fields.

Common Use Cases

  • Determine baseline calorie needs at rest
  • Use as foundation for TDEE and diet calculations
  • Compare metabolic rate changes with weight loss