The inverse problem in hydrodynamics of potential flow consists of finding velocity and wave pressures under assumption that a wavy surface elevation is known beforehand. The solution to this problem in both two and three dimensions is known but is based on theory of small-amplitude waves. Since some hydrodynamic problems involve waves of arbitrary amplitudes a more general solution is needed. In the paper such solution is given for two and three dimensions and it is shown that it is efficient from computational point of view and more accurate than the solution for smallamplitude waves.