Finite volume effects for the pion mass at two loops

We evaluate the pion mass in finite volume to two loops within chiral perturbation theory. The results are compared with a recently proposed extension of the asymptotic formula of Lüscher. We find that contributions, which were neglected in the latter, are numerically very small at the two-loop level and conclude that for MπL≳2MπL≳2, L⩾2 fmL⩾2 fm the finite volume effects in the meson sector are analytically well under control.