Loading...
Calculate your Basal Metabolic Rate (BMR) using Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle formulas. Get accurate daily calorie needs and personalized nutrition recommendations for your fitness goals.
Most accurate for general population (±10% accuracy)
Select your typical weekly activity level to calculate TDEE (Total Daily Energy Expenditure)
💡 These are calculated from your TDEE, not BMR
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, cell production, and nutrient processing. It represents 60-75% of your total daily calorie expenditure.
Think of BMR as your body's "idle" energy consumption—the minimum fuel needed to keep your engine running even when you're not moving.
The most accurate formula for the general population, developed in 1990. It has ±10% accuracy for most people.
Originally developed in 1919, revised in 1984. Still widely used with ±15% accuracy.
Best for lean, athletic individuals. Requires body fat percentage. Gender-neutral formula based on lean body mass.
Create a calorie deficit from your TDEE (not BMR). A 500-calorie deficit from TDEE equals approximately 1 lb/week loss.
Eat at your TDEE level. Monitor weight weekly and adjust by ±100-200 calories as needed.
Eat 250-500 calories above TDEE. Combine with strength training and adequate protein (1.6-2.2g/kg).
Men typically have 5-10% higher BMR due to more muscle mass
BMR decreases 1-2% per decade after age 20
Muscle burns 6 cal/lb/day vs 2 cal/lb/day for fat
Larger bodies require more energy to maintain
Can vary BMR by up to 20% between individuals
Cold exposure can increase BMR by 5-10%
Thyroid, cortisol, and growth hormone affect BMR
Chronic dieting can lower BMR by 10-15%
Poor sleep can reduce BMR by 5-20%
Muscle tissue burns 3x more calories than fat tissue at rest. Aim for 3-4 strength sessions per week.
Protein has the highest thermic effect (20-30% of calories burned during digestion). Aim for 1.6-2.2g per kg body weight.
Eating too little triggers metabolic adaptation, lowering BMR by 10-15%. Never eat below your BMR.
Drinking 500ml of water can temporarily boost metabolism by 10-30% for about an hour.
7-9 hours of sleep maintains hormonal balance. Poor sleep can reduce BMR by 5-20%.
High-intensity interval training can elevate metabolism for up to 24 hours post-workout (EPOC effect).
Caffeine and catechins can temporarily boost metabolism by 3-11%. Effects last 2-3 hours.
Chronic stress elevates cortisol, which can slow metabolism and promote fat storage.
BMR is the number of calories your body burns at rest to maintain vital functions like breathing, circulation, cell production, and nutrient processing. It represents the minimum energy your body needs to survive if you were to rest for 24 hours.
BMR is your resting metabolic rate, while TDEE (Total Daily Energy Expenditure) includes all calories burned through daily activities and exercise. TDEE = BMR × Activity Level Multiplier. TDEE is what you should use for diet planning.
The Mifflin-St Jeor equation is considered most accurate for the general population (±10% accuracy). Harris-Benedict is older but still reliable. Katch-McArdle is best for lean, athletic individuals as it accounts for body composition.
Use our calculator with your age, gender, weight, and height. The Mifflin-St Jeor formula is: Men: (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5. Women: (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161.
Yes, BMR typically decreases by 1-2% per decade after age 20 due to loss of muscle mass and hormonal changes. This is why maintaining muscle through strength training becomes increasingly important as you age.
Build muscle through strength training (muscle burns more calories at rest), eat enough protein, stay hydrated, get adequate sleep (7-9 hours), avoid extreme calorie restriction, and consider HIIT workouts. Muscle tissue burns 6 calories per pound daily vs. 2 for fat.
For safe weight loss, create a deficit from your TDEE (not BMR). A 250-500 calorie deficit from TDEE results in 0.5-1 lb/week loss. While eating slightly below BMR occasionally won't harm you, consistently eating well below BMR can slow metabolism and cause muscle loss. Always stay above 1200 calories/day for women and 1500 for men.
BMR varies based on age, gender, height, weight, muscle mass, genetics, and hormones. Men typically have higher BMR due to more muscle mass. Taller and heavier people have higher BMR. Muscle tissue is more metabolically active than fat.
This BMR calculator is provided for informational and educational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.
The calculations provided are estimates based on established scientific formulas (Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle equations) but may not be accurate for everyone, particularly those with medical conditions affecting metabolism.
Always consult with a qualified healthcare provider, registered dietitian, or certified nutritionist before:
Individual results may vary. Factors such as genetics, hormones, medications, sleep quality, stress levels, and underlying health conditions can significantly affect your actual metabolic rate.
If you experience unusual symptoms, extreme fatigue, rapid weight changes, or other health concerns while following any calorie recommendations, seek immediate medical attention.
Our BMR calculator uses scientifically validated formulas that have been peer-reviewed and widely accepted in the nutrition and fitness community:
This calculator is designed to provide quick, accessible estimates for general fitness and nutrition planning. For clinical or medical purposes, indirect calorimetry testing performed in a laboratory setting provides the most accurate BMR measurement.
Data Privacy: All calculations are performed in your browser. We do not store, collect, or transmit your personal health information.