Widmark's formula is used for estimating ?

Widmark evolved a formula which takes into account the size and sex of the person and the type of alcoholic liquor consumed. The formula is a = prc,where a, is weight of alcohol(in g)in the body,p,is the body weight(in kg);c, is the concentration of alcohol in the blood(in mg per kg);and r is a constant(0.6 for men and 0.5 for women) Ref: K.S.N.Reddy 29th Ed Page 516