Calculate your Basal Metabolic Rate – calories your body burns at rest
Your Basal Metabolic Rate (BMR) is the number of calories your body burns every day just to stay alive — even if you did nothing but lie in bed all day. It accounts for essential functions like breathing, blood circulation, cell production, and organ function. BMR typically accounts for 60–75% of total daily calorie expenditure.
Our calculator uses the two most widely accepted and scientifically validated equations: the Mifflin-St Jeor (recommended by most modern dietitians) and the classic Harris-Benedict formula. Enter your weight, height, age, and sex for an accurate estimate.
BMR = 10×75 + 6.25×175 − 5×30 + 5
= 750 + 1,093.75 − 150 + 5 = 1,698.75 calories/day
This person burns ~1,699 kcal daily just to maintain vital functions at rest.
BMR is your baseline calorie burn at rest. TDEE (Total Daily Energy Expenditure) = BMR × Activity Multiplier. If your BMR is 1,700 and you exercise 3x/week, your TDEE ≈ 1,700 × 1.55 = 2,635 kcal. TDEE is the number you should use for dietary planning. Use our TDEE Calculator to find your number.
Eating below your BMR for extended periods is not recommended. It can cause muscle loss, metabolic slowdown, nutritional deficiencies, and hormonal imbalances. Aim to create a calorie deficit of 300–500 kcal below your TDEE (not BMR) for sustainable fat loss.
Yes, BMR naturally decreases with age — roughly 2% per decade after age 30. This is primarily due to loss of muscle mass (sarcopenia). Strength training helps preserve muscle and maintain a higher BMR. This is why many people notice weight gain in their 30s–40s even without changing their diet.