Discover the number of calories your body burns at rest to tailor your nutrition and fitness goals.
Your Resting Metabolic Rate (RMR) is an estimate of how many calories your body burns while in a state of complete rest. It represents the minimum amount of energy needed to keep your vital organs and bodily systems functioning, including breathing, circulating blood, regulating body temperature, and basic brain functions. Knowing your RMR is the foundational first step in determining your total daily calorie needs, whether your goal is weight loss, muscle gain, or weight maintenance.
You may also hear the term Basal Metabolic Rate (BMR). RMR and BMR are very similar and often used interchangeably, but there's a slight technical difference. BMR is a more restrictive measurement taken in a dark, temperature-controlled lab after an overnight fast and a full, uninterrupted night of sleep. RMR is a less restrictive, more practical estimate of your resting energy expenditure and is typically about 10% higher than BMR. For most practical purposes, RMR is the more useful number for creating a real-world diet and exercise plan.
Your RMR is your metabolic baseline. To find your Total Daily Energy Expenditure (TDEE)—the total number of calories you burn in a typical day—you multiply your RMR by an activity factor. The calculator does this for you automatically, providing a clear path to setting your calorie targets:
This calculator uses the Mifflin-St Jeor equation, which is widely considered one of the most accurate methods for estimating Resting Metabolic Rate. Multiple studies have shown it to be more reliable than the older Harris-Benedict equation for a broader range of people.
While factors like age and genetics are fixed, you can boost your metabolism. The most effective way is through strength training to build more muscle mass. Muscle is more metabolically active than fat, meaning it burns more calories at rest. Eating enough protein, staying hydrated, and getting quality sleep also support a healthy metabolism.
No formula can be 100% accurate for every individual. This calculator provides a very strong scientific estimate that is highly useful for most people. The most precise way to measure RMR is through a clinical test called indirect calorimetry, but this is expensive and not easily accessible. For all practical purposes, this formula is an excellent starting point for your health journey.