BMR Calculation Formula

By using the simple formula below, called the Harris-Benedict principle, you can assess your Basal Metabolic Rate (BMR). It tells you how many calories you should consume in order to maintain your weight. Then, to lose weight, you'll need to cut calories from your diet or burn extra calories with exercise -- aiming for a level lower than the results you get with this formula.


Step 1: Calculate the appropriate formula for your sex (Please note that this formula applies only to adults):

  • Women:  655 + (4.3 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)
  • Men:  66 + (6.3 x weight in pounds) + (12.9 x height in inches) - (6.8 x age in years)


Step 2: Incorporate your activity level by adding a number from below to your BMR.

  • If you are sedentary: BMR x 20%
  • If you are lightly active: BMR x 30%
  • If you are moderately active (You exercise most days a week): BMR x 40%
  • If you are very active (You exercise intensely on a daily basis or for prolonged periods): BMR x 50%
  • If you are extra active (You do hard labor or are in athletic training): BMR x 60%


The result of this formula will be the number of calories you can eat every day and maintain your current weight. In order to lose weight, you'll need to take in fewer calories than this result. As you lose weight, you can re-calculate the formula to assess your new BMR.


For example, a woman who is 33 years old, 5'7" (which is 67 inches), weighs 130 pounds and is lightly active would calculate the formula like this:

655 + (4.3 * 130) + (4.7 * 67) - (4.7 *33) = 1374

Lightly active = 1374 * 30 = 412

So she could eat (1374 + 412) or 1786 calories per day to maintain her current weight.

If she wanted to lose weight she would need to eat less than 1786 calories per day or increase her activity level.