A baler having a compression system for forming a bale includes a plunger that reciprocates within a baling chamber between an extended position and a retracted position. The baler also includes a controller configured to detect and calculate the amount of work exerted by the plunger as it reciprocates within the baling chamber. The controller generally calculates the work exerted by the plunger by determining the force applied to the plunger and the distance the plunger has traveled with respect to the baling chamber.