BMR Calculator
Calories your body burns doing absolutely nothing.
Your Basal Metabolic Rate is the energy your body needs just to keep you alive — breathing, thinking, keeping warm. This calculator uses the widely trusted Mifflin-St Jeor equation. Knowing your BMR is the foundation for any calorie target, whether you're losing, maintaining or gaining.
How it's calculated
Mifflin-St Jeor: men 10×weight + 6.25×height − 5×age + 5; women the same minus 161 (weight in kg, height in cm).
Frequently asked questions
What is BMR vs TDEE?
BMR is what you'd burn lying in bed all day. TDEE (total daily energy expenditure) adds everything else — walking, working, exercising. Multiply BMR by an activity factor (see the daily calories calculator) to get TDEE.
How accurate is the Mifflin-St Jeor equation?
It's the most validated predictive formula, usually within about 10% for most people. Direct measurement (calorimetry) is more precise, but for planning purposes this is the accepted standard.
Does muscle really raise BMR?
Yes — muscle tissue burns more at rest than fat does. Two people at the same weight can have BMRs hundreds of calories apart depending on body composition, which is why strength training helps weight management.