BMR Calculator
Find your Basal Metabolic Rate — the calories your body burns at rest.
The BMR Calculator estimates your Basal Metabolic Rate — the energy your body burns at complete rest just to stay alive: heartbeat, breathing, brain function, cell repair and temperature regulation. Using the Mifflin-St Jeor equation, the most accurate common formula, it converts your weight, height, age and sex into a daily calorie figure.
BMR is the foundation of every calorie plan because it typically makes up 60–75% of total daily burn. Everything on top — walking, exercise, even digesting food — adds to it. That is why the same diet supports different weights in different bodies: the resting bill differs.
The result is a starting estimate, accurate to roughly ±10% for most people. The TDEE calculator builds on it with an activity multiplier for a full daily target. Runs entirely in your browser.
BMR (resting)
1,717.5 kcal/day
Mifflin-St Jeor formula
Per week
12,022.5 kcal
resting energy only
Approx per meal
572.5 kcal
if spread over 3 meals
BMR is the energy your body burns at complete rest — just keeping you alive. It is the base your total daily burn builds on; add activity with the TDEE calculator.
How to use the BMR Calculator
- Choose your sex.
- Enter your weight in kilograms, height in centimeters and age.
- Read your BMR in calories per day.
- Check the weekly and per-meal breakdown for planning.
- Move to the TDEE calculator to add your activity level.
Frequently asked questions
What is the Mifflin-St Jeor equation?
For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women: the same with −161 instead of +5. It replaced the older Harris-Benedict formula and is considered the best simple estimator for most adults.
What is the difference between BMR and TDEE?
BMR is energy at complete rest. TDEE (total daily energy expenditure) adds activity: BMR × an activity factor of 1.2–1.9. Use BMR to understand your baseline; use TDEE to set calorie targets.
Why do two people with the same stats have different BMRs?
Muscle mass, genetics, hormones, recent dieting history and body composition all shift metabolism by up to ±10–15%. Treat the formula as a good starting point and adjust based on what the scale actually does.
Related tools
View all health & fitness calculators →BMI Calculator
Calculate your Body Mass Index and see the healthy weight range for your height.
HealthTDEE Calculator
Total Daily Energy Expenditure — the calories you need to maintain your weight.
HealthMacro Calculator
Split your daily calories into protein, carbs and fat targets.
HealthCalorie Deficit Calculator
Plan your daily calorie target and the time to reach your goal weight.
HealthBody Fat Calculator
Estimate body fat percentage from tape measurements — no special equipment.
HealthIdeal Weight Calculator
Ideal body weight by formula plus the healthy BMI range for your height.