What size conduit for a 240 volt 50 amp wire?

For a 240 volt, 50 amp circuit, you typically use a minimum of 3/4 inch conduit for copper wire and 1 inch conduit for aluminum wire, assuming you are using THHN or THWN wire. The specific size may vary based on the number of conductors and any bends in the conduit. Always consult local electrical codes and the National Electrical Code (NEC) for precise requirements and adjustments based on your specific installation conditions.