Stocking density is a prominent topic in public debates on animal welfare and was one of the reasons for the European Commission to set limits to the stocking density on broiler farms. The objective of this paper was to calculate in detail the financial impact of changes in technical and management variables due to decreasing stocking densities in line with new European Union (EU) regulations. Therefore, the productive performance indicators such as BW, mortality, or feed conversion and farm technical data such as water consumption and heating of 3 independent experiments conducted at a poultry research station in Flanders (Belgium) were combined. Using the partial budget technique only those elements that change with stocking density have been taken into account. Reducing stocking density implies a recalculation of all costs on a reduced number of birds. This yields an economic situation that leaves hardly any profit margin for most of the broiler producers under the present market conditions. It was found that the critical threshold of stocking density for maintaining profitability under the present market and technical conditions is around 46 kg/m(2), thus well above the EU maximum of 42 kg/m(2). It is shown, however, that with changing broiler feed and meat prices, the impact might be less negative in economic terms.