The paper is concerned with the calculation of electrostatic potential and fields for realistic engineering problems, involving multidielectric materials and electrodes with sharp edges. The authors draw attention to a finite-difference algorithm for complex electrostatic problems which can be efficiently implemented on mainframe or personal computers without loss of accuracy. It is shown that data structures are easier with finite differences than with finite elements and finite-difference calculations can be carried out in complex regions to a high degree of accuracy, keeping the computational time and matrix size comparable with the requirements for finite elements. The software routines are described. The first routine is the main iterative solution scheme. A second routine recalculates potentials within a defined area of interest, with greater accuracy and greater detail. The application of the routines is illustrated by practical examples involving axisymmetric two-dimensional geometries. The accuracy of the results is tested by comparison with analytical solutions, measurements on resistance paper with silver, and finite-element solutions.