Basal Metabolic Rate (BMR) Calculator
Calculate your Basal Metabolic Rate (BMR), the number of calories your body needs to perform basic life-sustaining functions at rest.
What is Basal Metabolic Rate (BMR)?
Basal Metabolic Rate (BMR) is the minimum amount of energy (calories) your body needs to keep functioning while at rest. This includes essential processes like breathing, circulating blood, controlling body temperature, cell production, and brain activity. It's the energy your body expends if you were to lie in bed all day without doing anything else.
Understanding your BMR is a crucial first step in managing your weight and overall health. It helps you determine the baseline calorie intake your body requires. Your total daily energy expenditure (TDEE) is your BMR plus the calories burned through physical activity and the thermic effect of food.
How BMR is Calculated
The most common and widely accepted formulas for calculating BMR are the Harris-Benedict Equation and the Mifflin-St Jeor Equation. We use the Mifflin-St Jeor Equation here, as it is generally considered more accurate for the modern population.
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
Factors Affecting BMR
- Body Composition: Muscle tissue burns more calories at rest than fat tissue.
- Age: BMR generally decreases with age.
- Gender: Men typically have a higher BMR than women due to higher muscle mass.
- Genetics: Your inherited genes can influence your metabolic rate.
- Body Size and Shape: Larger individuals generally have a higher BMR.
Example Calculation
Let's calculate the BMR for a 35-year-old male who weighs 80 kg and is 180 cm tall:
- Weight: 80 kg
- Height: 180 cm
- Age: 35 years
- Gender: Male
Using the Mifflin-St Jeor Equation for men:
BMR = (10 × 80) + (6.25 × 180) – (5 × 35) + 5
BMR = 800 + 1125 – 175 + 5
BMR = 1755 calories per day