RMR same as BMR?
They differ in lab conditions, but many calculators use the same formula for both.
RMR Calculator
Estimate resting metabolic rate—the calories your body burns at rest before activity.
Estimate your RMR
Enter sex, age, height, and weight. RMR here uses the Mifflin-St Jeor equation (often used interchangeably with BMR).
About this calculator
How to use RMR Calculator, plus the formulas and logic behind the results.
Tool description
Resting Metabolic Rate (RMR) is energy spent on basic functions—breathing, circulation, cell repair—while at rest. Lab RMR differs slightly from BMR, but Mifflin-St Jeor is a practical online estimate.
How to use
- Select units.
- Enter sex, age, height, and weight.
- Calculate to see RMR in kcal/day.
- Compare with TDEE tools to add activity.
Formulas & reference
Men: RMR = 10×kg + 6.25×cm − 5×age + 5Women: RMR = 10×kg + 6.25×cm − 5×age − 161
RMR vs BMR
- BMR — stricter rest conditions in lab settings
- RMR — slightly higher; measured under relaxed rest
- Online calculators often use the same equations for both
Calculation logic
Inputs convert to metric, then the Mifflin-St Jeor equation returns kcal/day at rest.
Thyroid issues, illness, and very low body fat can shift real RMR away from equation estimates.
RMR Calculator FAQ
Common questions about this calculator and how to use the results.
Why Mifflin-St Jeor?
It performs well for general population estimates compared with older Harris-Benedict defaults.
Fasted measurement?
Not required for this estimate—it's based on height, weight, age, and sex.
How do I get TDEE from RMR?
Multiply by an activity factor (see TDEE or Maintenance calculators).
Very muscular?
Equations may underestimate needs; track intake and weight to fine-tune.
Medical use?
For clinical nutrition, indirect calorimetry is more accurate than any equation.