To calculate your daily calorie needs is to determine basal metabolic rate (BMR) using multiple factors, including height, weight, age and gender, then multiply the BMR by an activity factor to determine your total daily energy expenditure (calories). One calculation method is the Harris Benedict formula.

The Harris Benedict equation is a calorie formula using the variables of height, weight, age, and gender to calculate basal metabolic rate (BMR). This is more accurate than calculating calorie needs based on total body weight alone. The only factor it omits is lean body mass and thus the ratio of muscle-to-fat a body has. Remember, leaner bodies need more calories than less leaner ones. Therefore, this equation will be very accurate in all but the very muscular (Harris-Benedict will under-estimate calorie needs) and the very obese (Harris-Benedict will over-estimate calorie needs).

Two Steps to Determine Daily Calorie Needs

• First, determine your BMR.
• Second, apply the Activity Multiplier.

Formula for Women

661 + (4.38 x weight in lb.) + (4.38 x height in inches) – (4.7 x age) = BMR

Example of BMR
You are 38 years old
You are 5 feet 6 inches tall
Your weight is 155 pounds
Your BMR is 661 + (679) + (289) - (179) = 1450 calories

Remember to make your calculations in the parentheses first

Once you have your BMR, to determine your total daily calorie needs, now multiply your BMR by the appropriate activity factor, as follows:

• If you are Sedentary - little or no exercise
  Calorie-Calculation = BMR X 1.2
• If you are Lightly Active (light exercise/sports 1-3 days/week)
  Calorie-Calculation = BMR X 1.375
• If you are Moderately Active (moderate exercise/sports 3-5 days/week)
  Calorie-Calculation = BMR X 1.55
• If you are Very Active = BMR X 1.725 (hard exercise/sports 6-7 days/week)
  Calorie-Calculation = BMR X 1.725

Keep in mind that to loose 1 pound of stored body fat a week you would need to create a 3500 calorie deficiency through both diet and exercise.