This page provides information on how to perform the relevant calculations to find out the various important numbers you need to know and work along with regarding caloric intake to lose fat and gain muscle.
They include Basal Metabolic Rate (BMR), Total Daily Energy Expenditure (TDEE), Number of Calories To Gain Weight and Number Of Calories To Lose Weight.
Note: Some of the calculations are based on formulas that require some mathematical input, but I also include a link to various calculation tools that have been developed to help make the process easier. All you need to do is put in the required data into the calculator and it will perform the calculations for you.
1. Basal Metabolic Rate (BMR) or Resting Metabolic Rate (RMR) – Calculate the number of calories that your body burns in a day while you are resting.
This is the number of calories your body would expend while at rest, when you are not doing any physical activity at all. According to Bodybuilding.com “the release of energy in this state is sufficient only for the functioning of the vital organs, such as the heart, lungs, brain and the rest of the nervous system, liver, kidneys, sex organs, muscles and skin”.
The following are the formulas used to calculate BMR for men and women.
Women: BMR = 655 + 4.35 x weight (in pounds) + 4.7 x height (in inches ) – 4.7 x (age in years)
Men: BMR = 66 + 6.23 x weight (in pounds) + 12.7 x height (in inches) – 6.8 x age (in years)
There is also a tool that you can use that will perform the calculation for you. Click here to go to the calculator tool on webmd.com. To find your basal metabolic rate (BMR) put in the required information in the BMR calculator on the site
2. Total Daily Energy Expenditure (TDEE ) – Calculate the total number of calories that your body burns per day for your BMR plus all the physical activities that you do.
This is the number of calories you need to consume to stay alive and healthy every day without losing or gaining weight. You need to know this number because any significant subtraction of calories from this number will result in weight loss and any significant addition will result in weight gain.
To calculate your TDEE , multiply your BMR by the figure for the appropriate activity factor that suits your lifestyle:
Estimate your activity factor:
Sedentary: means that you perform very little exercise or don’t exercise at all
Lightly active: means that you engage in light exercise or sports 1-3 days per week.
Very active: means that you engage in fairly strenuous exercise or sports 6-7 days a week
Extra active: means that you have a physical job where you are very active throughout the day.
Multiply your BMR by the figure for your activity level. The total that you get will be your TDEE.
Sedentary (little or no exercise): BMR x 1.2 = Your TDEE
Lightly active (light exercise/sports 1-3 days/week): BMR x 1.375 = Your TDEE
Moderately active (moderate exercise/sports 3-5 days/week): BMR x 1.55 = Your TDEE
Very active: BMR x 1.725 = Your TDEE
Extra active (very hard exercise/sports and physical job or 2x training): BMR x 1.9 = Your TDEE
If you prefer, you can Click here go to a tool that’ll do the calculation for you to find your TDEE.
So once you’ve figured out your TDEE, the number that you get is a number of calories your body burns on an average day to keep you alive and energetic without changing your weight.
Modifying that number by increasing will make you gain weight (build muscle when resistance training is applied) and modifying that number by decreasing will make you lose weight.
3. Calculate the number of calories you need to eat per day to lose weight
This is the number of calories you’ll need to eat per day to be able to lose weight which should be body fat (not muscle) in order to get a lean body. That number must be less than your Total Daily Energy Expenditure (TDEE).
The number of calories that you need to eat per day to lose weight would be determined based on a variety of factors. However, in order to lose one pound of fat, you must have a deficit of 3500 calories.
Therefore, the idea is to lose a pound of fat gradually over a period of time by cutting a certain amount of calories from your total daily caloric requirement, but at the same time making sure that the deficit would not cause negative effects to your body.
How many calories to eat less daily?
As I said the number of calories you should eat less each day to lose weight would be affected by a number of factors, but cutting 500 calories per day from your TDEE is a safe number to start with, and it would allow you to lose about a pound of fat per week.
A good fat loss program would help you properly create a calorie deficit with strategic nutrition planning and the use of exercise to allow you to lose body fat without negative consequences.
4. Calculate the number of calories you need to eat per day to gain weight
You’ll need to know this number to be able to gain weight, which should be muscle if you are weight training properly. Again, this number may vary considerably based on your goals and individual circumstances.
However, as a good starting point, you can eat 250-500 calories a day more than your TDEE to gain muscle with a good weight training program that you are following properly.
Another common method used to calculate required daily calories intake to gain weight and build muscle is multiplying your body weight in pounds by a figure between 16-20. For example, if you weigh 160 lbs, multiply 160 x 18 you’ll have a caloric number for weight gain.
So now that you have an idea of the number of calories that you need to eat to maintain, lose and gain weight, the next step is to start tracking your calorie intake to figure where you are and how you need to adjust your diet to achieve the right surplus or deficit in accordance with your goals.