Find your resting calorie burn — Mifflin & Harris-Benedict
Personal Information
Biological Sex
Formula
Your BMR Result
Daily Calorie Need (TDEE)
Moderately Active (3–5 days/week)
Formula Comparison
Activity Multipliers
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest — just to keep your organs functioning. It accounts for roughly 60–70% of total daily energy expenditure. Multiply by your activity factor to get your TDEE (Total Daily Energy Expenditure), which is the calorie total you need to maintain your current weight.
Mifflin-St Jeor (Male)
10w + 6.25h − 5a + 5
Mifflin-St Jeor (Female)
10w + 6.25h − 5a − 161
Harris-Benedict (Male)
88.362 + 13.397w + 4.799h − 5.677a
Harris-Benedict (Female)
447.593 + 9.247w + 3.098h − 4.330a
w = weight (kg), h = height (cm), a = age (years)
Note: BMR estimates are based on population-level equations and may not reflect individual metabolic variation. Actual calorie needs depend on body composition, health conditions, and other factors. Consult a healthcare professional or registered dietitian for personalised guidance.
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at rest to maintain basic life functions. Our free BMR calculator supports both the Mifflin-St Jeor and Harris-Benedict equations — the two gold-standard formulas used by dietitians. Enter your age, sex, height, and weight to instantly see your BMR and TDEE across all activity levels.
BMR (Basal Metabolic Rate) is the number of calories your body needs at complete rest to keep organs functioning — breathing, circulation, cell repair, and temperature regulation. It typically accounts for 60–70% of your total daily calorie burn, making it the foundation for any diet or fitness plan.
The Mifflin-St Jeor equation (1990) is generally considered more accurate for most people and is preferred by dietitians today. The Harris-Benedict equation (revised 1984) tends to overestimate BMR slightly but remains widely cited. For the best estimate, use Mifflin-St Jeor unless your nutritionist specifies otherwise.
Multiply your BMR by an activity multiplier to get your TDEE (Total Daily Energy Expenditure). To lose weight, eat 300–500 kcal below your TDEE. To gain muscle, eat 200–300 kcal above. To maintain, match your TDEE. The calculator computes all of this automatically when you select your activity level.
Yes. BMR typically decreases about 1–2% per decade after age 20 as lean muscle mass naturally declines. This is reflected in the formulas — the age term reduces BMR over time. Strength training can help preserve muscle mass and slow this metabolic decline.