Mc-Pher-son
This morning my son asked me “If our last name is McPherson, why do people always call us McPhearson?”
“I don’t know,” I replied. Besides the “Mc” there are no tricks; the pronunciation follows the standard English reading rules.
I know that text on a page is not the best medium for a pronunciation guide (at least until we all learn IPA), so here’s a read aloud:
Related: How to pronounce my name