What size wire do you need to run a 50 amp electrical box for a small shop?

Be safe and run 6 gauge wire although 8 gauge will handle 50 amps at short distances. I assume this is a 220 volt circuit and the small shop is within 100 feet of the power source. === === <><><>

As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed. Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized. IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.