Finite-element results for C, the nondimensional shape factor which relates stress drop to fault offset, are presented for rectangular strike-slip and two dimensional strike-slip and dip-slip faults at various depths of burial. All faults were oriented vertically except for a two-dimensional fault which was dipped at 10°. The finite-element meshes were constructed to limit the error in C to 1 per cent, as demonstrated by comparison with the analytical solution for a circular fault in an infinite region. Attainment of such accuracy results in large, finite-element matrix equations which were solved by a fast iterative technique: the multi-grid method. For the rectangular faults, significant differences were seen in values of C between the finite-element results and some previously reported solutions which were obtained by a different numerical technique.