Your basal metabolic rate is the amount of energy (in calories) your body needs to function at rest. The Harris-Benedict formula is used to estimate the basal metabolic rate. There is one formula for adult males and another for adult females. In these formulas w is your body weight in pounds, h is your height in inches, a is your age in years,

M = M(w, h, a)

is the basal metabolic rate for adult males, and

F = F(w, h, a) is the basal metabolic rate for adult females: