BMR Calculator
Estimate your Basal Metabolic Rate (BMR) — roughly how many calories your body burns at complete rest — using the Mifflin-St Jeor formula.
Estimated Basal Metabolic Rate
1370 kcal/day
This is roughly how many calories your body burns at complete rest just to keep basic functions running — it does not include any activity. For calories burned in a typical day including activity, see the TDEE Calculator. This is a formula-based estimate, not a measurement of your actual metabolism or medical advice.
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How to use bmr calculator
- 1Enter your sex, age, height and weight (metric or imperial).
- 2Read your estimated BMR in calories per day.
About this tool
BMR is an estimate of the energy your body needs just to keep basic functions running — breathing, circulation, cell production — while completely at rest, with no activity factored in at all. It's the foundation that the TDEE and Calorie calculators build on by multiplying BMR by an activity level.
This calculator uses the Mifflin-St Jeor equation, published in 1990 and generally considered more accurate for most people today than the older 1919 Harris-Benedict equation it's usually compared against.
BMR naturally varies with age, sex, height, weight and muscle mass, and this formula only accounts for the first four — actual measured BMR (via indirect calorimetry) can differ from the formula's estimate. Use it as a reasonable approximation, not an exact figure.
Frequently asked questions
BMR is calories burned at complete rest with zero activity. TDEE takes that BMR and multiplies it by an activity factor to estimate total calories burned in a typical day, including exercise and daily movement — TDEE is always higher than BMR.