What is Basal Metabolic Rate (BMR)?
Basal Metabolic Rate (BMR) is the amount of energy (calories) your body expends at complete rest to maintain vital functions: breathing, circulation, body temperature regulation, nervous system function, and cell renewal. BMR accounts for 60-75% of total daily energy expenditure and depends on gender, age, height, weight, and body composition.
How to Use the BMR Calculator?
Enter your weight, height, age, and gender for basic calculation. For more accurate results, specify body fat percentage - this will account for the ratio of muscle to fat mass. The calculator will determine your BMR and Total Daily Energy Expenditure (TDEE) accounting for physical activity level, which is necessary for nutrition planning.
What is BMR Calculation Used For?
- Planning nutrition for weight loss or muscle gain
- Calculating optimal calorie deficit or surplus to achieve goals
- Determining baseline macronutrient needs (proteins, fats, carbohydrates)
- Optimizing sports nutrition accounting for training load
Frequently Asked Questions About Basal Metabolic Rate
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is calorie expenditure at complete rest, only for maintaining vital functions. TDEE (Total Daily Energy Expenditure) is total daily energy expenditure, including BMR plus energy costs for daily activity, training, and thermic effect of food (digestion). TDEE is usually 1.2-2.0 times higher than BMR depending on activity level.
How does body fat percentage affect BMR calculation accuracy?
Muscle tissue is metabolically significantly more active than fat tissue (approximately 3 times). Two people with the same weight but different body fat percentages will have different BMR. An athlete with low body fat will have higher BMR. Standard formulas without accounting for body composition can give errors up to 10-15%.
Why does BMR decrease with age?
With age, natural muscle mass loss occurs (sarcopenia) - approximately 3-8% per decade after age 30, and overall metabolism slows down. This leads to BMR decrease by approximately 2-3% every 10 years. Strength training and maintaining muscle mass help slow this decline.