According to the United States Census Bureau, the township has a total area of 11.1 square miles (28.9 km2), of which, 11.0 square miles (28.5 km2) of it is land and 0.1 square miles (0.3 km2) of it (1.08%) is water.
Emmaus and Allentown share a border, separating Salisbury into two demographically-distinct non-contiguous portions.