To calculate your own Basal Metabolic Rate (BMR), you can use the Harris-Benedict or Mifflin-St Jeor equations, which consider factors like weight, height, age, and gender. After choosing an equation and gathering the necessary information, plug in the numbers to get your BMR. This is just the starting point for understanding your daily calorie needs, as you also need to consider your activity level. Multiply your BMR by activity factors based on how active you are to estimate your total daily energy expenditure.
How to Calculate Your Own Basal Metabolic Rate (BMR)
Basal Metabolic Rate (BMR) is the amount of energy expended while at rest in a neutrally temperate environment, in the post-absorptive state. In other words, it's the minimum number of calories your body needs to maintain basic physiological functions like breathing, circulation, and cell production when you are at rest. Calculating your BMR can help you understand how many calories your body burns daily without any physical activity. Here are the steps to calculate your BMR:
Harris-Benedict Equation
The Harris-Benedict equation is one of the most widely used methods to estimate BMR. It takes into account factors such as weight, height, age, and gender.
##### For Men:
\[ BMR = 88.362 + (13.397 \times weight \text{ in kg}) + (4.799 \times height \text{ in cm}) - (5.677 \times age \text{ in years}) \]
##### For Women:
\[ BMR = 447.593 + (9.247 \times weight \text{ in kg}) + (3.098 \times height \text{ in cm}) - (4.330 \times age \text{ in years}) \]
Mifflin-St Jeor Equation
Another popular method is the Mifflin-St Jeor equation, which many consider to be more accurate than the Harris-Benedict equation.
##### For Men:
\[ BMR = (10 \times weight \text{ in kg}) + (6.25 \times height \text{ in cm}) - (5 \times age \text{ in years}) + 5 \]
##### For Women:
\[ BMR = (10 \times weight \text{ in kg}) + (6.25 \times height \text{ in cm}) - (5 \times age \text{ in years}) - 161 \]
Steps to Calculate Your BMR
1. Choose an Equation: Decide which equation you want to use. Both the Harris-Benedict and Mifflin-St Jeor equations are reliable, but some people may find one more accurate for them than the other.
2. Gather Information: You need your weight in kilograms (1 pound = 0.45359237 kg), your height in centimeters (1 inch = 2.54 cm), your age in years, and your gender.
3. Plug in the Numbers: Use the equation you chose and fill in your information.
4. Calculate: Do the math to get your BMR. This is the estimated number of calories your body burns at rest.
5. Consider Activity Level: Your BMR is just the starting point. To maintain your current weight, you need to consume enough calories to cover both your BMR and your physical activities. Multiply your BMR by the following activity factors to estimate your total daily energy expenditure (TDEE):
- Sedentary (little or no exercise): BMR x 1.2
- Lightly active (light exercise/sports 1-3 days a week): BMR x 1.375
- Moderately active (moderate exercise/sports 3-5 days a week): BMR x 1.55
- Very active (hard exercise/sports 6-7 days a week): BMR x 1.725
- Extra active (very hard exercise/sports & physical job or 2x training): BMR x 1.9
By following these steps, you can calculate your own basal metabolic rate and gain insights into your daily calorie needs based on your individual characteristics and lifestyle.