BMR (Basal Metabolic Rate)

Basal Metabolic Rate (BMR) is a calculation of your gender, age, height and weight. It is an easy way to calculate your caloric intake based solely on your body weight. Although it leaves out lean body mass, it measures out the body's muscle to fat ratio. For the average sized body the BMR is extremely accurate. However, for larger bodies (both muscular and fat) it can be inaccurate in determining your caloric needs. For the muscular body type, the BMR can underestimate the number of calories needed, and for the overweight body type it can overestimate the number of calories needed.

Imperial BMR Formula
Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )

Metric BMR Formula
Women: BMR = 655 + ( 9.6 x weight in kilos ) + ( 1.8 x height in cm ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 13.7 x weight in kilos ) + ( 5 x height in cm ) - ( 6.8 x age in years )