Zakharov and Shafranov’s method for deriving plasma displacement and averaged shape in a tokamak from magnetic probes positioned along a contour around the plasma cross section is extended in several ways. Formulas are derived which allow vertical as well as horizontal displacements with any ratio of minor contour width to major radius, asymmetric as well as symmetric multipole moments, and explicit relations for rectangular as well as circular contours. The relations in the literature for a circular contour are also re‐examined and corrected equations are given. It is shown that a rectangular contour can provide the same information.