Mifflin-St Jeor
Male: (10 × W) + (6.25 × H) − (5 × A) + 5
Female: (10 × W) + (6.25 × H) − (5 × A) − 161
Harris-Benedict
Male: 66.47 + (13.75 × W) + (5 × H) − (6.76 × A)
Female: 655.1 + (9.563 × W) + (1.85 × H) − (4.676 × A)
Katch-McArdle
RMR = 370 + (21.6 × LBM)
Requires body fat percentage
W = Weight (kg), H = Height (cm), A = Age (years), LBM = Lean Body Mass (kg)
Little or no exercise
Light exercise 1-3 days/week
Moderate exercise 3-5 days/week
Hard exercise 6-7 days/week
Very hard exercise, physical job
Resting Metabolic Rate (RMR) represents the number of calories your body burns while at complete rest to maintain vital functions such as breathing, circulation, cell production, and nutrient processing. It accounts for approximately 60-75% of your total daily energy expenditure, making it the largest component of your metabolism.
Unlike Basal Metabolic Rate (BMR), which is measured under strict conditions after fasting and sleeping, RMR is measured under less restrictive conditions and is slightly higher. For practical purposes, the terms are often used interchangeably since the difference is typically only 10-20%.
BMR
Basal Metabolic Rate - measured in a completely rested state after 8 hours of sleep and 12 hours of fasting.
RMR
Resting Metabolic Rate - similar to BMR but measured under less strict conditions, typically 3-4 hours after eating.
TDEE
Total Daily Energy Expenditure - your RMR multiplied by an activity factor to account for daily movement and exercise.
- Muscle Mass: More muscle tissue requires more energy to maintain, increasing RMR.
- Age: RMR typically decreases with age, partly due to loss of muscle mass.
- Gender: Men generally have higher RMR due to greater muscle mass and less body fat.
- Body Size: Larger bodies require more energy to maintain basic functions.
- Hormones: Thyroid hormones significantly affect metabolic rate.
- Temperature: Cold environments can increase RMR as the body works to maintain temperature.
RMR calculations are estimates based on standard formulas and may vary depending on individual metabolism, health factors, and body composition. These values should be used as a starting point and adjusted based on real-world results. For personalized nutrition and fitness advice, consult with a healthcare provider or registered dietitian.