BMR Calculator
Find your basal metabolic rate — the calories your body burns at complete rest — using the Mifflin-St Jeor equation, then see your daily needs at different activity levels.
How to use it
Enter your age, sex, height and weight to get your BMR: the energy your body uses just to stay alive. For most people this is the single largest part of daily calorie burn, before any movement or exercise is added.
To turn BMR into the calories you actually need each day, multiply by an activity factor — that's your TDEE. Use our calorie calculator to do that and to get eating targets for your goal.
Frequently asked questions
What is BMR?
Basal metabolic rate is the number of calories your body uses at rest to keep basic functions going — breathing, circulation and cell repair. It's the largest part of most people's daily calorie burn.
What formula does this use?
The Mifflin-St Jeor equation, widely regarded as one of the most accurate for healthy adults: 10 × kg + 6.25 × cm − 5 × age, then +5 for men or −161 for women.
What's the difference between BMR and TDEE?
BMR is calories burned at rest. TDEE (total daily energy expenditure) is BMR multiplied by an activity factor to include movement and exercise — that's the figure to base eating targets on.
BriskToolbox provides estimates for general information only and is not medical advice. Talk to a healthcare professional about your individual health.