Resting Metabolic Rate Calculator

Resting Metabolic Rate (RMR) is the number of calories your body burns at rest to maintain basic physiological functions like breathing, circulation, cell production, and nutrient processing. It accounts for 60-75% of your total daily energy expenditure. RMR is similar to Basal Metabolic Rate (BMR), but BMR is measured under stricter conditions (immediately upon waking, in a fasted state). RMR is slightly higher and more practical for everyday use. Understanding your RMR helps you create appropriate nutrition plans for weight loss, maintenance, or muscle gain.

The Mifflin-St Jeor equation is currently considered the most accurate for the general population, with approximately +/-10% accuracy. It was developed in 1990 and has been validated in numerous studies. The Harris-Benedict equation (revised in 1984) is also reliable but slightly less accurate. The Katch-McArdle formula is most accurate for athletic individuals or those with known body fat percentages, as it uses lean body mass rather than total body weight. For most people, Mifflin-St Jeor provides the best estimate without requiring body composition testing.

You can increase your RMR through several methods: 1) Build muscle mass through resistance training - muscle tissue burns more calories at rest than fat tissue (about 6 cal/lb/day vs 2 cal/lb/day). 2) Eat enough protein - it has a higher thermic effect than carbs or fats. 3) Stay hydrated - water is essential for metabolic processes. 4) Get adequate sleep - sleep deprivation can decrease RMR by 2-8%. 5) Avoid extreme calorie restriction - very low-calorie diets can decrease RMR by 10-20%. 6) Include interval training - HIIT can elevate metabolism for hours post-exercise. Genetics plays a significant role, but these factors can optimize your metabolic rate.

To lose weight, create a calorie deficit by consuming fewer calories than your Total Daily Energy Expenditure (TDEE = RMR * activity factor). A safe deficit is 500 calories per day for 1 lb/week loss, or 1000 calories for 2 lbs/week. Never eat below your RMR for extended periods, as this can slow metabolism and cause muscle loss. Instead, create the deficit through a combination of diet (300-500 cal reduction) and exercise (200-500 cal burned). Track your progress weekly and adjust as needed. Aim for 0.5-1% body weight loss per week for sustainable results while preserving muscle mass.