BMR Calculator
Discover how many calories your body burns at rest using the Mifflin-St Jeor equation.
How this BMR calculator works
Your Basal Metabolic Rate is calculated using the Mifflin-St Jeor equation, the formula recommended by the Academy of Nutrition and Dietetics for estimating resting energy expenditure. For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For women: the same formula minus 161 instead of adding 5.
What the result means
Your BMR is the baseline for all calorie calculations. To find your actual daily needs, use the TDEE calculator which multiplies your BMR by your activity level. From there you can set a calorie target for cutting, maintaining, or bulking.
Frequently Asked Questions
- What is BMR?
- Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic physiological functions — breathing, circulation, cell repair — at complete rest.
- Which BMR formula does this calculator use?
- This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate formula for most people. It accounts for weight, height, age, and biological sex.
- How does BMR differ from TDEE?
- BMR is your calorie burn at rest. Total Daily Energy Expenditure (TDEE) multiplies BMR by an activity factor to account for your actual daily movement and exercise.
- Does BMR change over time?
- Yes. BMR decreases with age (roughly 2–3% per decade after 20) and can decrease during prolonged calorie restriction. Building muscle mass can increase BMR slightly.