Calculate your Basal Metabolic Rate, the calories your body burns at rest, using the Mifflin-St Jeor and Harris-Benedict formulas.
Load representative profiles to check ranges:
Fill in your physical attributes to predict resting energy expenditure baselines.
This is the minimum energy required to keep your body alive at rest with no physical movements.
Understanding basal calories and the metabolic mechanisms driving daily energy burn.
BMR represents the baseline amount of thermal energy required to keep your body functional in a resting state. It accounts for about 60% to 75% of your total daily energy output.
Your organs (liver, brain, heart, kidneys) utilize the majority of resting baseline energy, even when you are asleep.
BMR is your resting metabolic rate. Total Daily Energy Expenditure (TDEE) factors in physical activity and digestive processes.
Several physiological factors regulate BMR:
For men, BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5. For women, the same terms are used but 161 is subtracted instead of adding 5. This equation, published in 1990, is generally considered the more accurate default for most modern adults.
This calculator uses the 1984 Roza and Shizgal revision of the original 1918 Harris-Benedict formula: for men, BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) - (5.677 x age); for women, BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) - (4.330 x age). It tends to produce a slightly higher result than Mifflin-St Jeor for the same inputs.
For a 30-year-old man who is 178 cm tall and weighs 75 kg, Mifflin-St Jeor gives roughly 1,718 kcal/day, while the revised Harris-Benedict formula gives roughly 1,777 kcal/day for the same inputs. Both are resting-only estimates and exclude any calories burned through movement or exercise.
BMR only reflects energy needs at complete rest, so multiply it by an activity factor using the Calorie Calculator or TDEE Calculator to estimate realistic total daily calorie needs for weight maintenance, loss, or gain.
Quick answers about how this tool works.
Plain-language explainers that sit next to this tool.
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