  Standard methods for including electromagnetic interactions in lattice
quantum chromodynamics calculations result in power-law finite-volume
corrections to physical quantities. Removing these by extrapolation requires
costly computations at multiple volumes. We introduce a photon mass to
alternatively regulate the infrared, and rely on effective field theory to
remove its unphysical effects. Electromagnetic modifications to the hadron
spectrum are reliably estimated with a precision and cost comparable to
conventional approaches that utilize multiple larger volumes. A significant
overall cost advantage emerges when accounting for ensemble generation. The
proposed method may benefit lattice calculations involving multiple charged
hadrons, as well as quantum many-body computations with long-range Coulomb
interactions.
