The present basis for determining the protein value in pig feeds is discussed and a proposal for a new protein evaluation system is presented. The system proposed includes (i) a quantification of digestible amino acids according to their ileal digestibility, determined using standardized methods; (ii) a characterization of the protein value according to the contribution of digestible amino acids to ideal protein; (iii) a calculation of surplus amino acid‐N; and (iv) a calculation of the physiologically available energy of surplus amino acids.