Harris Benedict Calculation Overview
The Harris Benedict Equation should not be used in a vacuum. Combine the HBE with your BMR (basal metabolic rate) to find how many calories you burn each day.
How to apply the Harris Benedict Equation
The Harris Benedict Calculation is a formula that uses your BMR and then applies an activity factor to determine your total daily energy expenditure (calories). The only factor omitted by the Harris Benedict Equation is lean body mass. Remember, leaner bodies need more calories than less lean ones. Therefore, this equation will be very accurate in all but the very muscular (will underestimate calorie needs) and the very fat (will over-estimate calorie needs). Here are the activity levels to perform the harris benedict calculation:
Activity Chart:
Activity: Little/no exercise: Calorie-Calculation = BMR x 1.2
Activity: Light exercise/sports 1-3 days/week: Calorie- Calculation = BMR x 1.375
Activity: Moderate exercise/sports 3-5 days/week: Calorie-Calculation = BMR x 1.55
Activity: Hard exercise/sports 6-7 days/week: Calorie-Calculation = BMR x 1.725
Activity: Very hard exercise/sports & physical job: Calorie-Calculation = BMR x 1.9
Harris Benedict Equation Example:
Say Alex has a BMR of 1800. This means that if Alex stayed in bed all day Alex's calorie consumption would be 1800 calories per day. Alex exercises 1-3 days/week so we have to look at the 'Activity Chart' above to find the correct multiplier:
Equation: 1800 x 1.375 = 2475 Calories/Day
Thanks to both the application of the BMR and Harris Benedict equation we now have a complete picture of how many calories Alex will burn in day with sleep and exercise included.
Putting it all together:
This calorie calculator finds your daily calorie expenditure need taking into account your nutrition goal. It first dins your BMR, then applies the Harris Benedict Equation to give you the number of calories you need to consume each day to achieve your weight gain or weight loss goal.