an efficient method for calculation of the exciton states in type-i superlattices is developed and demonstrated. the model, based on the work of dignam & sipe [phys. rev. b 43,4097 (1991)], includes bound and quasi-continuous two-well exciton eigenstates as a basis in which to expand the superlattice exciton eigenstates. this basis is used to calculate the excitonic absorption spectra for two different type-i superlattices as a function of the applied static field. the results are found to be in very good agreement with the experimental results of holfeld et. al [phys. rev. lett. 81, 874 (1998)] for the 67a/17a superlattice and with those of agullo-rueda et. al [phys. rev. b 41, 1676 (1990)] for the 40a/40 a superlattice. on the basis of these results, this method should be ideal for use in the calculation of nonlinear and coherent effects in optically excited semiconductor superlattices.