We propose a modification of the standard van der Pauw method for determining the resistivity and Hall coefficient of flat thin samples of arbitrary shape. Considering a different choice of resistance measurements we derive a formula which can be numerically solved (with respect to sheet resistance) by the Banach fixed point method for any values of experimental data. The convergence is especially fast in the case of near-symmetric van der Pauw configurations (e.g., clover shaped samples). (C) 2012 Elsevier B.V. All rights reserved.