BMR calculator
Your basal metabolic rate, plus daily burn at every activity level.
Basal metabolic rate
What your BMR is and why it matters
Your Basal Metabolic Rate (BMR) is the energy your body burns at complete rest just to keep you alive: breathing, circulation, and basic cell function. It is the largest part of your daily calorie burn and the starting point for any nutrition plan.
The formula
BMR (women) = 10×kg + 6.25×cm − 5×age − 161
To estimate the calories you actually burn in a day, multiply BMR by an activity factor: 1.2 if sedentary, up to 1.725 if very active. That gives your TDEE, shown in the result panel for several activity levels.
Frequently asked questions
What is BMR?
Basal Metabolic Rate is the number of calories your body uses at rest over 24 hours to maintain essential functions. It does not include any activity.
How is BMR calculated?
This calculator uses the Mifflin-St Jeor equation, which estimates BMR from your weight, height, age, and sex. It is widely regarded as the most accurate everyday formula.
What is the difference between BMR and TDEE?
BMR is calories burned at rest. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor, giving the full amount you burn including movement and exercise.
Why does BMR matter?
It is the foundation of calorie planning. Knowing your BMR and TDEE tells you roughly how much to eat to maintain, lose, or gain weight.
Does BMR change with age?
Yes. BMR tends to fall slowly with age, partly because muscle mass declines. Strength training helps preserve muscle and keep metabolism higher.