The Harris-Benedict Equation for calculating calorie needs.
Use the appropriate formula for men or women..
Men: BMR = 66 + (13.7 x W) + (5 x H) - (6.8 x Age) = Daily calories required
Women: BMR = 665 + (9.6 x W) + (1.8 x H) - (4.7 x Age) = Daily calories needs
Where:
W = weight in Kgs Convert body weight here!
H = Height in cms ( 1 foot = 12 inches, 1 inch = 2.54 cms)
Age = Years
An example for a 30 year old women weighing 80 (176 pounds) Kgs and 5 foot 6 inches tall would be..
665 + (9.6 x 80) + (1.8 x 168) - (4.7 x 30)
665 + 768 + 302 - 141 = 1594 calories per day!
The values in the above equation are based on averages within the population. Therefore the problem with this equation is it doesn't take into account the amount of lean body weight a person may have. For this reason people who are very muscular or those who are obese may not obtain a very accurate calculation of BMR. Muscular individuals may need more calories than the formula suggests and, very overweight people may need less than the calories needs from the calculation.
The above equation calculates calorie needs for the BMR, you still need to work out calorie requirements for the day including any activities.
Multiply your BMR by an activity factor which more closely suits your lifestyle
Sedentary - none or very little exercise = BMR X 1.2
Light activity for average of 2 days/week = BMR X 1.375
Moderate activity level exercising 4 days/week = BMR X 1.5
High activity levels exercise & sports more than 6 days/week = BMR X 1.7
Higher activity levels = up to 2 x BMR