  We calculate the self-energy of the Delta (1232) resonance in a finite
volume, using chiral effective field theory with explicit spin-3/2 fields. The
calculations are performed up-to-and-including fourth order in the small scale
expansion and yield an explicit parameterization of the energy spectrum of the
interacting pion-nucleon pair in a finite box in terms of both the quark mass
and the box size L. It is shown that finite-volume corrections can be sizeable
at small quark masses.
