Electromagnetic forward and inverse solvers are considered for the analysis and design of electromagnetic metasurfaces. This paper reviews (i) a forward solver that takes the surface susceptibilities of metasurfaces and calculates their scattered fields and (ii) an inverse solver that takes user-defined desired power patterns and outputs the required metasurface properties. An omega-bianisotropic transmitting metasurface is then fabricated and measured to evaluate the performance of these forward and inverse solvers.