Basal Metabolic Rate (BMR) Calculator
What is Basal Metabolic Rate (BMR)?
Basal Metabolic Rate (BMR) is the minimum amount of energy your body needs to function at rest. This includes vital functions like breathing, circulating blood, regulating body temperature, and cell production. Think of it as the energy your body burns just to keep you alive, even if you were to sleep all day.
Why is BMR Important?
Understanding your BMR is a crucial first step in managing your weight and overall health. Your total daily energy expenditure (TDEE) is your BMR plus the energy you burn through physical activity and the thermic effect of food. Knowing your BMR helps you estimate how many calories you need to consume to maintain, lose, or gain weight.
- Weight Loss: Consuming fewer calories than your TDEE, which is heavily influenced by BMR.
- Weight Gain: Consuming more calories than your TDEE.
- Maintenance: Consuming roughly the same number of calories as your TDEE.
How is BMR Calculated?
The most commonly used formulas to estimate BMR are the Harris-Benedict Equation and the Mifflin-St Jeor Equation. The Mifflin-St Jeor Equation is generally considered more accurate for most people. This calculator uses the 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:
- Muscle Mass: More muscle mass increases BMR.
- Age: BMR typically decreases with age.
- Gender: Men generally have a higher BMR than women due to typically higher muscle mass.
- Body Size: Larger bodies require more energy.
- Genetics: Individual genetic makeup plays a role.
- Hormones: Thyroid hormones, in particular, significantly influence metabolism.
- Body Temperature: Higher body temperature increases BMR.
Example Calculation:
Let's calculate the BMR for a 35-year-old male who weighs 80 kg and is 180 cm tall.
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