Kinetic simulations are used to compute current characteristics of finite-length cylindrical probes, with particular attention to end effects. Currents collected per unit lengths, as a function of distance to the ends, are calculated and fitted to empirical analytic functions. These fits, in turn, can be interpolated and used to predict probe characteristics; that is, collected current as a function of applied voltage, for a broad range of physical parameters of relevance to laboratory and space plasma.