Your basal metabolic rate (BMR) is the number of calories your body burns at complete rest just to keep you alive: breathing, circulating blood, repairing cells and regulating temperature. For most people it makes up 60 to 70% of the calories they burn each day.
BMR Calculator
Shows both the Mifflin-St Jeor and revised Harris-Benedict equations.
What Is BMR?
BMR is the minimum energy your body needs at rest. It is the foundation of every calorie calculation. Your total daily calories (TDEE) are your BMR plus the energy you use moving, exercising and digesting food.
BMR Formulas Explained
Mifflin-St Jeor (1990) is considered the most accurate everyday equation for most adults:
- Men: (10 x weight in kg) + (6.25 x height in cm) – (5 x age) + 5
- Women: (10 x weight in kg) + (6.25 x height in cm) – (5 x age) – 161
Harris-Benedict (revised 1984) is an older formula that tends to estimate slightly higher. We show both so you can compare.
What Affects Your BMR?
- Muscle mass: Muscle burns more energy than fat, even at rest, so strength training can raise your BMR.
- Age: BMR falls gradually with age, partly due to muscle loss.
- Sex: Men usually have a higher BMR because they tend to carry more muscle.
- Body size: Larger bodies need more energy to maintain.
- Genetics and hormones: Thyroid hormones in particular play a big role.
How to Use Your BMR
Don’t eat below your BMR for long periods without medical guidance. To set a calorie target, multiply your BMR by your activity level with our calorie calculator, then split it into protein, carbs and fat with the macro calculator.
Frequently Asked Questions
What is a normal BMR?
Most adult women have a BMR between about 1,200 and 1,500 calories, and most men between about 1,500 and 1,900, depending on size, age and muscle.
Is BMR the same as RMR?
They are very close. RMR (resting metabolic rate) is measured under less strict conditions and is usually slightly higher than BMR.
How can I increase my BMR?
Build muscle with strength training, eat enough protein, stay active and get good sleep. Crash dieting can lower it.
Should I eat my BMR calories to lose weight?
No. Eating only your BMR is usually too low. Aim for a moderate deficit below your TDEE instead.
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