Understanding Metabolic Rate
Metabolic rate refers to the rate at which your body burns calories to perform its basic life-sustaining functions, such as breathing, circulation, cell production, and nutrient processing. This baseline rate is known as your Basal Metabolic Rate (BMR). Your BMR represents the number of calories your body needs to function at rest.
However, your total daily energy expenditure (TDEE) is higher than your BMR because it also accounts for the calories you burn through physical activity and the thermic effect of food (the energy used to digest and absorb food).
This calculator helps you estimate your BMR using the Mifflin-St Jeor equation, which is widely considered one of the most accurate methods. It then uses your chosen activity level to estimate your TDEE.
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
Calculating TDEE:
To estimate your Total Daily Energy Expenditure (TDEE), your BMR is multiplied by an activity factor that reflects your typical daily physical activity. The activity factors used in this calculator are standard estimates:
- Sedentary: Little or no exercise, desk job.
- Lightly Active: Light exercise or sports 1-3 days per week.
- Moderately Active: Moderate exercise or sports 3-5 days per week.
- Very Active: Hard exercise or sports 6-7 days per week.
- Extra Active: Very hard exercise or sports and a physical job.
Understanding your metabolic rate can be a valuable tool for managing your weight, whether your goal is to lose, gain, or maintain it. By knowing how many calories your body burns, you can make more informed decisions about your diet and exercise routines.