Purpose: Calculate your Basal Metabolic Rate - the number of calories your body needs at complete rest - using the accurate Mifflin-St Jeor equation.
BMR Calculator
The BMR Calculator finds your Basal Metabolic Rate - the calories your body burns at complete rest just to stay alive - using the trusted Mifflin-St Jeor equation.
What BMR represents
Your BMR is the energy needed for breathing, circulation, cell repair, and brain function while at rest - typically 60–70% of the calories you burn each day. The Mifflin-St Jeor formula estimates it from your sex, age, height, and weight, and is considered more accurate for modern populations than the older Harris-Benedict equation.
Turning BMR into a plan
BMR alone is not your daily calorie need - you multiply it by an activity factor to get your total (TDEE), which is what you use for weight goals. The Calorie Estimator does that next step. Knowing your BMR helps you understand why crash diets that drop far below it are hard to sustain and can slow metabolism.
Frequently Asked Questions
What is the difference between BMR and TDEE?
BMR is the calories burned at rest; TDEE adds the calories burned through activity. TDEE is your actual daily maintenance level.
Which equation does it use?
The Mifflin-St Jeor equation, widely regarded as more accurate for today's population than the older Harris-Benedict formula.
Should I eat only my BMR calories to lose weight?
No. Eating at or below BMR long-term is hard to sustain and can slow metabolism. Base weight-loss targets on your TDEE with a moderate deficit.
What lowers or raises BMR?
More muscle mass raises BMR; ageing and losing muscle lower it. Sex, height, and weight also affect the figure.
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