Experiments with broiler chickens usually compare the effects of treatments when birds are killed at the same time. However, producers need to know the value of treatments on birds killed at the same weight, since their goal is to produce birds for a certain market. The curve expressing body weight as a function of feed consumption is described very well by a second-order polynomial (quadratic curve). Given an observed body weight and feed intake and a standard curve, it is possible to produce a curve that describes the relationship of body weight to feed consumption for any flock. Once this curve is estimated for a flock, it is possible to estimate the feed consumption (and therefore feed conversion or efficiency) for any weight of bird that could be slaughtered.