Please go to the following link if you’re looking for the free online BMR calculator tool.
The Harris Benedict Equation, also called the Harris Benedict Principle, is a multi step formula that is used to determine an individual’s calorie requirements on a daily basis using their Basal Metabolic Rate (BMR).
No equation like this can be 100% accurate, but it provides a solid estimate. The accuracy is skewed because the equation does not account for the amount of muscle mass or the amount of body fat a person has.
Both of these conditions affect the BMR and amount of calories the body burns/needs per day. Therefore, the Harris Benedict Equation determines the amount of calories needed for an individual that falls within the ideal body weight or a weight within a range of ideal body weights.
The Harris Benedict Equation is commonly used to help people lose weight. After calculating the number of calories needed per day, a person can simply decrease the amount of calories to an amount slightly less than the calculated total.
First, the person’s BMR needs to be established. The BMR can be found by calculating it by hand or using a BMR calculator. The BMR formula includes multiplying your weight, height and age by predetermined numbers, unique to both men and women.
Next, you multiply the BMR by a predetermined number based on the amount of exercise the individual does on a daily or weekly basis. There are five different categories.
First, the BMR is multiplied by 1.2 if the person does little to no exercise. If the person exercises one to three times per week, BMR is multiplied by 1.375. Exercising three to five times a week, 1.55 is multiplied by the previous determined BMR. Heavy exercise consisting of six or seven days per week has a multiplication factor of 1.725.
Finally, very heavy exercise, which details working out twice a day, including extra strenuous sessions, requires multiplying the BMR by 1.9.
The product of the BMR and the five different multiplication factors will give you the amount of calories required on a daily basis.
Wikipedia was relied upon as a source for this article: http://en.wikipedia.org/wiki/Harris-Benedict_equation.