Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to keep you alive — breathing, circulating blood, and maintaining temperature. It usually accounts for 60–70% of the calories you burn each day.
This calculator uses the Mifflin-St Jeor equation, the formula most dietitians consider the most accurate for the general population:
Men: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5
Women: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161
BMR is calories at rest. To estimate how many calories you actually burn in a day — your Total Daily Energy Expenditure (TDEE) — multiply your BMR by an activity factor:
| Activity level | TDEE |
|---|---|
| Sedentary (little or no exercise) | BMR × 1.2 |
| Lightly active (1–3 days/week) | BMR × 1.375 |
| Moderately active (3–5 days/week) | BMR × 1.55 |
| Very active (6–7 days/week) | BMR × 1.725 |
| Extra active (hard training / physical job) | BMR × 1.9 |
To lose weight, eat below your TDEE; to gain, eat above it. Pair this with the macronutrient and steps tools below to build a full plan.
A BMR calculator estimates your Basal Metabolic Rate — the calories your body needs at rest. Enter your weight, height, age, and sex, and it applies the Mifflin-St Jeor formula to return your daily resting calorie burn.
Use the Mifflin-St Jeor equation: 10×weight(kg) + 6.25×height(cm) − 5×age, then add 5 for men or subtract 161 for women. The calculator above does this automatically in metric or imperial units.
BMR is the calories you burn at complete rest. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor and represents everything you burn in a day, including movement and exercise.
Yes. The Mifflin-St Jeor formula adds 5 for men and subtracts 161 for women, reflecting differences in average body composition. Men typically have a higher BMR than women of the same height, weight, and age.
The Mifflin-St Jeor equation (used here) is generally considered the most accurate for most people. The older Harris-Benedict equation tends to slightly overestimate. For very lean or muscular individuals, the Katch-McArdle formula (based on lean body mass) can be more precise.