BMR Calculator
Your BMR is the number of calories your body burns at complete rest, just to keep you alive. It's the foundation of every calorie calculation — find yours with the trusted Mifflin–St Jeor equation.
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BMR vs TDEE
Your BMR is the resting floor; TDEE adds your daily activity.
BMR stands for Basal Metabolic Rate — the energy your body uses at rest to run essential functions like breathing, circulation, and cell repair. It typically accounts for 60–70% of the calories you burn each day. This calculator uses the Mifflin–St Jeor equation, widely regarded as the most accurate BMR formula for the general population, and shows how your BMR compares to your full daily burn.
How BMR is calculated
The Mifflin–St Jeor equation estimates BMR from your weight, height, age, and sex. For men it's 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5; for women the same formula ends with − 161 instead of + 5. It's the formula dietitians reach for most often because studies have found it more accurate than older equations like Harris–Benedict.
Because BMR reflects the energy of simply being alive, it rises with more body mass (especially muscle) and generally declines with age. It doesn't include any movement — that's where TDEE comes in.
BMR vs TDEE — and why you need both
Your BMR is the floor of your energy needs; your TDEE is the full picture. To get from one to the other, multiply your BMR by an activity factor that accounts for movement and exercise. The comparison bar on this page shows the gap between them for your stats.
You'll rarely set your calorie intake at your BMR — eating that little would leave no fuel for activity. Instead, BMR is the building block: calculate it first, then layer on activity to find your TDEE, then adjust for your goal.
Frequently Asked Questions
BMR, or Basal Metabolic Rate, is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production. It's usually 60–70% of your total daily calorie burn.
This calculator uses the Mifflin–St Jeor equation: for men, 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5; for women, the same but − 161 at the end. It's considered the most accurate BMR formula for most people.
BMR is the calories you burn at rest. TDEE is your BMR plus all your daily activity and exercise. To find TDEE, multiply your BMR by an activity factor between 1.2 and 1.9.
No. Eating at your BMR leaves no energy for daily activity and is usually too aggressive. Base your intake on your TDEE minus a sensible deficit instead.
As you age you tend to lose muscle mass, which is metabolically active tissue, and your organ activity slows slightly. Both lower your BMR, which is why the Mifflin–St Jeor equation subtracts calories for each year of age.
These results are estimates for general educational purposes only and are not medical or nutritional advice. Individual needs vary. Consult a qualified healthcare professional or registered dietitian before making significant changes to your diet, especially if you are pregnant, breastfeeding, under 18, or have a medical condition.