BMR & Calorie Calculator
Estimate your basal metabolic rate and daily calorie needs.
Your basal metabolic rate is the energy your body burns at rest. Enter your gender, age, weight and height to estimate your BMR and your daily calorie needs at different activity levels.
Formula / method
Examples
≈ 1,649 kcal
≈ 1,320 kcal
What your BMR represents
Basal Metabolic Rate is the number of calories your body burns at complete rest to keep essential systems running — breathing, circulation, cell repair and staying warm. For most people it accounts for the majority of daily calorie use, well before any exercise is added.
The Mifflin-St Jeor equation
This calculator uses the Mifflin-St Jeor formula, widely regarded as the most accurate simple estimate for the general population. It combines weight, height, age and sex, because each affects how much energy your body needs at rest. Muscle mass raises BMR, which is one reason estimates are only a guide.
To turn BMR into the calories you actually burn in a day, multiply it by an activity factor — that is what the related TDEE Calculator does.
Where it's used
- Setting a daily calorie target for weight loss, maintenance, or gain
- Planning macronutrient splits for a diet or meal-prep plan
- Estimating baseline energy needs before starting a cutting or fitness program
- Dietitians and trainers giving clients a starting calorie figure
- Seeing how calorie needs change with age, sex, or after losing weight
Real-world examples
- A 30-year-old man, 70 kg and 175 cm, gets a BMR of about 1,649 kcal, rising to roughly 2,556 kcal a day at a moderate activity level.
- A 45-year-old woman, 65 kg and 160 cm, reads her BMR and subtracts about 500 kcal/day to aim for roughly 0.5 kg of loss per week.
- Comparing two people of the same weight and height shows the older one needs fewer resting calories, since BMR falls with age.
A bit of history
This tool uses the Mifflin-St Jeor equation, published in 1990 by M.D. Mifflin and S.T. St Jeor. It largely replaced the older Harris-Benedict equation of 1919, developed by James Arthur Harris and Francis Gano Benedict.
Did you know?
For most people, basal metabolism accounts for the majority of the calories burned each day, typically more than physical activity and digesting food combined.
FAQ
What is BMR?
Basal metabolic rate is the energy your body uses at complete rest. Multiply it by an activity factor to estimate your total daily calorie needs.