Find out exactly how many calories your body burns at rest. Your Basal Metabolic Rate (BMR) is the foundation of any nutrition plan — from weight loss to muscle building.
Your BMR appears here
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Your metabolic baseline drives every nutrition decision.
Never eat below your BMR for extended periods. Your body burns these calories just to survive — cutting below this triggers muscle breakdown, hormonal disruption, and metabolic adaptation that makes future fat loss harder.
Your Total Daily Energy Expenditure (TDEE = BMR × activity multiplier) is the number that actually matters for weight management. Eat 300–500 kcal below your TDEE to lose fat. Eat above it to build muscle.
Each kg of muscle burns approximately 13 kcal/day at rest. Adding 5 kg of muscle raises your BMR by ~65 kcal/day — making it easier to maintain a healthy weight long-term without constant calorie restriction.
Your Basal Metabolic Rate is the number of calories your body requires to maintain basic physiological functions — breathing, circulation, temperature regulation, and cellular repair — while completely at rest. It accounts for approximately 60–75% of your total daily caloric expenditure, making it the dominant factor in energy balance.
This calculator uses the Mifflin-St Jeor equation, the gold standard formula validated by the American Dietetic Association as the most accurate for estimating BMR in non-obese individuals. It was developed in 1990 from studies of over 500 people and provides estimates within ±10% of measured BMR for most adults.
BMR and metabolism explained.
BMR is the calories burned at complete rest. TDEE (Total Daily Energy Expenditure) multiplies BMR by your activity level to estimate total daily calorie burn. TDEE is the number you use for weight management decisions.
It is accurate within ±10% for most adults. It tends to slightly overestimate BMR for very obese individuals and underestimate for very muscular people. Re-calculate as your weight changes.
Yes. Resistance training builds muscle, which raises resting metabolic rate. Adequate protein intake preserves muscle during caloric deficit. High-intensity interval training (HIIT) also elevates post-exercise oxygen consumption (EPOC), temporarily raising metabolic rate for hours after exercise.
The primary cause is sarcopenia — the gradual loss of muscle mass that begins around age 30 (0.5–1% per year). Since muscle is metabolically active, less muscle means lower BMR. Resistance training can largely prevent and even reverse this decline.
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