Equation comparison
See the formulas together, including each equation’s difference from the selected headline and from a measured RMR when provided.
| Equation | Estimate | vs headline | vs measured RMR | Inputs used |
|---|
OneFreePlace · Tool #137
Compare resting-energy equations instead of trusting one unexplained number.
Calculate Mifflin–St Jeor and revised Harris–Benedict side by side, add Cunningham when lean mass is available, inspect formula disagreement, compare against a measured resting metabolic rate, and convert the result into kcal/day, kJ/day, kcal/hour and watts.
✓ 3 equation families✓ Body-fat / lean-mass mode
✓ Measured-RMR comparison✓ Formula sensitivity lab
✓ No activity multiplier
BMR Calculator
Mifflin · revised Harris–Benedict · Cunningham · measured comparison
Profile
Enter the inputs used by the equations.
Body composition · optionalUnlocks the Cunningham lean-mass equation.
Headline methodChoose which available equation appears as the primary result.
Measured resting metabolism · optionalFor indirect-calorimetry or other measured RMR results.
Selected resting-energy estimate
Calculating—
kcal / day
Enter valid adult profile information.
Kilojoules / day—1 kcal = 4.184 kJ
Calories / hour—daily estimate ÷ 24
Average power—energy rate equivalent in watts
Per kg body weight—selected estimate ÷ body weight
Display sensitivity band—user-selected ± band, not a statistical confidence interval
Equation spread—available equations
Estimate, not measurementNo activity multiplier is used. This tool intentionally stops at resting energy so it does not duplicate the TDEE or calorie-target tools.
Body-composition lab
When body composition is available, lean mass becomes visible rather than being hidden inside age/height/sex coefficients.
Formula sensitivity lab
These are equation responses—not predictions of how your metabolism will actually change. Each row changes one input while holding the others constant.
| Scenario | Selected equation | Change | Interpretation |
|---|
Measured RMR comparison
If you have a measured value, this turns the tool into an equation audit instead of making you manually compare numbers.
Equation audit
Exact formulas used by this page. Weight is kg, height is cm, age is years, and FFM is fat-free mass in kg.
Mifflin–St Jeor · 1990
Male: 10W + 6.25H − 5A + 5
Female: 10W + 6.25H − 5A − 161Revised Harris–Benedict · Roza & Shizgal, 1984
Male: 88.362 + 13.397W + 4.799H − 5.677A
Female: 447.593 + 9.247W + 3.098H − 4.330ACunningham lean-mass equation · 1991
REE = 370 + 21.6 × FFMWhat this number is—and is not
Resting-energy estimatePrediction equations approximate energy expenditure at rest from population data.
EstimatedTrue BMR measurementRequires tightly controlled basal conditions; consumer profile equations do not measure it.
Not measuredTDEE / daily calorie needIncludes activity and other daily expenditure. Deliberately excluded from Tool #137.
Separate tooli
Adult calculator, not a diagnosis or metabolic test.Pregnancy, breastfeeding, adolescence, illness, fever, endocrine conditions, major weight change, medications and other factors can shift measured resting energy. Use measured indirect calorimetry or clinician guidance when precision is medically important.