Basal Metabolic Rate (BMR) Calculator
Your Basal Metabolic Rate (BMR) is the minimum number of calories your body needs to perform basic life-sustaining functions at rest. This includes breathing, circulation, cell production, and nutrient processing. Understanding your BMR is crucial for managing your weight and overall health, as it forms the foundation of your daily caloric needs.
Understanding Basal Metabolic Rate (BMR)
Your Basal Metabolic Rate (BMR) represents the energy expenditure of your body at complete rest, in a neutrally temperate environment, and in a post-absorptive state. It's essentially the number of calories your body burns to keep your vital organs functioning, such as your heart, lungs, brain, and nervous system. This baseline calorie burn is a significant component of your total daily energy expenditure.
Several factors influence your BMR, including:
- Age: BMR generally decreases with age.
- Gender: Men typically have a higher BMR than women due to having more muscle mass.
- Body Composition: Muscle tissue burns more calories at rest than fat tissue.
- Body Size: Larger individuals generally have a higher BMR.
- Genetics: Individual metabolic rates can vary due to genetic factors.
The most common formulas used to estimate BMR are the Harris-Benedict Equation (revised in 1984) and the Mifflin-St Jeor Equation (considered more accurate by many). This calculator uses the Mifflin-St Jeor Equation.
Mifflin-St Jeor Equation:
- For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
- For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
Once you know your BMR, you can estimate your Total Daily Energy Expenditure (TDEE) by multiplying your BMR by an activity factor that reflects your lifestyle (e.g., sedentary, lightly active, moderately active, very active). This TDEE is the total number of calories you need to maintain your current weight.