BMR Calculator
Estimate the calories your body uses at rest and learn how your personal details influence your baseline energy needs.
Calculate your BMR
Enter your age, gender, height and weight. Choose metric for centimetres and kilograms, or imperial for inches and pounds.
Enter your details to see your estimated basal metabolic rate.
What Does BMR Mean?
Basal metabolic rate, or BMR, is the estimated number of calories your body needs to perform essential functions while at complete rest. These functions include breathing, circulation, temperature regulation and maintaining your organs.
How is BMR calculated?
This calculator uses the Mifflin–St Jeor equation, a commonly used formula. For men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5. For women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161.
Factors Affecting BMR
BMR can vary from person to person. Age, body size, height, muscle mass, genetics, hormones, illness, temperature and long-term changes in energy balance can all influence how much energy your body uses at rest. The result is an estimate rather than a direct measurement.
BMR vs TDEE
Total daily energy expenditure, or TDEE, estimates your complete daily calorie needs by combining BMR with physical activity, exercise and the energy used to digest food. BMR is your resting baseline; TDEE is a broader estimate of your total daily needs. To estimate TDEE, BMR is commonly multiplied by an activity factor.
Related Health Information
BMR works alongside other health measures and should not be treated as a diagnosis or a prescription. For another useful estimate, try our BMI Calculator to compare your weight with your height.
Frequently Asked Questions
Is BMR the same as resting metabolic rate?
They are closely related concepts, but they are measured under slightly different conditions. This calculator provides an estimate of BMR rather than a laboratory measurement.
Can I use BMR as my daily calorie target?
BMR does not include normal movement or exercise, so it is not a complete daily calorie target. TDEE is a better starting estimate for total daily needs.
Why does gender appear in the calculation?
The Mifflin–St Jeor equation uses different constants based on sex because average body composition and energy requirements differ. The result remains an estimate for an individual.
How accurate is this calculator?
Formula-based calculators provide a useful estimate, but individual results can vary. A qualified healthcare professional can help interpret your energy needs in context.