We study the self-entanglement of a single linear polymer chain with N monomers confined to a cubic box (L x L x L) using the bond-fluctuation lattice model and primitive path analysis. We probe chains with N between 30 and 750 and vary the degree of confinement L/R-g0 between 0.4 and 12, where R-g0 is the radius of gyration of an unconfined polymer. We find that the conformational properties R-g/R-g0 and L-p/R-g0, where L-p is the average primitive path length, collapse onto a single master curve as a function of the degree of confinement. In the strongly confined regime, L/R-g0 < 1, we find that R-g/R-g0 similar to (L/R-g0)(0.8) and (L-p/R-g0) similar to (L/R-g0)(-2). We verify that the simulation methodology used is quantitatively consistent with experimental data, and the Colby-Rubinstein entanglement model for unconfined concentrated polymer solutions. The most significant difference between unconfined and confined systems is the variation of L-p with monomer density phi; L-p similar to phi(5/9), in the former, and L-p similar to phi(2/3), in the latter. (C) 2014 Wiley Periodicals, Inc.