BMR & TDEE Calculator

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to maintain essential life functions such as breathing, blood circulation, and cell production. It represents the minimum energy your body needs to survive without any physical activity. For most adults, BMR ranges from 1,200 to 2,400 calories per day depending on body size, age, sex, and muscle mass. BMR typically accounts for 60 to 75 percent of your total daily energy expenditure.

BMR measures only the calories burned at complete rest, while TDEE (Total Daily Energy Expenditure) represents your total calorie burn throughout the day. TDEE is calculated by multiplying your BMR by an activity multiplier that accounts for exercise, daily movement, and the thermic effect of food (calories burned during digestion). You should use TDEE — not BMR — when setting calorie goals for weight loss, maintenance, or muscle gain.

Several factors influence your BMR. Age causes a decline of approximately 2 percent per decade after age 20. Muscle mass is a major factor — more muscle tissue requires more energy to maintain. Males typically have a 5 to 10 percent higher BMR than females due to greater average muscle mass. Genetics play a role, and hormones — particularly thyroid function — can significantly raise or lower metabolic rate. Body size, body composition, and certain medical conditions also affect BMR.

The most effective way to increase BMR is to build muscle through resistance training, since each pound of muscle burns approximately 6 calories per day at rest compared to 2 calories for fat. Staying well-hydrated supports metabolic processes, and getting adequate sleep (7 to 9 hours) helps regulate metabolic hormones. Eating sufficient protein supports muscle maintenance and has a higher thermic effect than carbs or fats. Avoid extreme calorie restriction, as it can lower your BMR significantly over time.