An economic model was developed that calculates economic optimal dietary balanced protein (DBP) contents for broiler chickens, based on performance input and prices of meat and feed. Input on broiler responses to DBP content (growth rate, feed conversion, carcase yield and breast meat yield) was obtained from the model described by Eits et al. (2005). Changes in broiler age, price of protein-rich raw materials and large changes (40%) in meat prices resulted in economic relevant differences in DBP content for maximum profit. Effects of changes in sex or feed price on DBP content for maximum profit were negligible. Formulating diets for maximum profit instead of maximum broiler performance can strongly increase the profitability of a broiler production enterprise. DBP content for maximum profitability depends on how the broilers are marketed; as whole birds, carcase or portions.