BMR Calculator
Calculate your Basal Metabolic Rate to understand how much energy your body requires at rest. Essential for planning effective nutrition strategies.
Calculator Inputs
Mifflin-St Jeor is generally considered more accurate for modern populations.
Did you know?
Your brain accounts for about 20% of your BMR despite representing only 2% of your body weight.
What is Basal Metabolic Rate (BMR)?
Your Basal Metabolic Rate (BMR) is the minimum number of calories your body needs to perform basic, life-sustaining functions while at complete rest. Even when you are sleeping or sitting perfectly still, your body is hard at work burning calories to:
- Pump blood throughout your body
- Breathing and lung function
- Maintain body temperature (thermogenesis)
- Cell growth and repair
- Brain and nervous system function
For most people, BMR accounts for approximately 60% to 75% of total daily calorie expenditure. Knowing this number is the starting point for any weight loss or weight gain plan.
Variables Affecting BMR
Muscle Mass
Muscle burns more calories than fat, even at rest. Building muscle increases your BMR.
Age
Metabolism generally slows down as you age, partly due to loss of muscle tissue.
Gender
Men typically have higher BMRs than women due to larger body size and higher muscle mass.
Genetics
Some people are simply born with a "faster" or "slower" metabolism.
BMR vs. RMR
You might hear the terms BMR and RMR (Resting Metabolic Rate) used interchangeably, but there is a slight difference:
- BMR is measured under very restrictive conditions: immediately after waking up, in a darkened room, after 8 hours of sleep and 12 hours of fasting.
- RMR is measured under less strict conditions and doesn't require the subject to spend the night at the testing facility.
For practical purposes of weight management, the difference is negligible, and BMR calculators like this one provide a sufficient estimate for setting up a diet plan.
Frequently Asked Questions
Frequently Asked Questions
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