The results of simulations for future measurements of electromagnetic form factors at \PANDA (FAIR) in frame of the PandaRoot software are reported. The statistical precision at which the proton form factors can be determined is estimated. The signal channel $\bar p p \to e^+ e^-$ is studied on the basis of two different but consistent procedures. The main background is identified in the $\bar p p \to \pi^+ \pi^-$ channel. The suppression of this background, the background versus signal efficiency, and the of the statistical errors on the extracted proton form factors have been also evaluated according to the two different procedures. The comparison with older predictions based on an old framework shows consistency of the results and a slightly better precision is achieved here in a large range of momentum transfer, assuming the nominal conditions of beam and detector performances.