What's the difference between RMR and BMR?
BMR is measured in complete rest after fasting. RMR is slightly higher, measured in rested state. Difference is ~10%.
Health Fitness
Resting Metabolic Rate Calculator
Estimate resting metabolic rate with quick inputs.
Fast, practical estimates
Adjust inputs for the most useful result.
What this calculator does
Resting Metabolic Rate (RMR) is calories burned at rest, slightly higher than BMR due to measurement conditions. RMR represents 60-75% of daily energy expenditure and is foundational for calculating total calorie needs.
How it works
Mifflin-St Jeor equation uses weight, height, age, and sex. Multiply by activity factor for TDEE.
Formula
Men: (10×kg) + (6.25×cm) - (5×age) + 5. Women: (10×kg) + (6.25×cm) - (5×age) - 161.
Tips for using this calculator
- RMR and BMR are often used interchangeably
- Muscle mass increases RMR
- Severe calorie restriction lowers RMR
- RMR decreases with age and weight loss
- Lab testing provides most accurate RMR
Frequently asked questions
Why does RMR decrease with dieting?
Metabolic adaptation—body becomes more efficient to conserve energy. Gradual weight loss minimizes this effect.
Can I increase my RMR?
Building muscle increases RMR. Each pound of muscle burns ~6 calories/day at rest vs ~2 for fat.