I have a 500 Amp service panel. One 250 AMP breaker is being used for the house and the other 250AMP breaker is not being used.

I would like to connect to the unused 250AMP breaker and run 240V to a sub panel 244 feet away where I will have a hot tub 50AMPS and a 30AMP draw for a trailer or a 100 AMP total draw at the sub panel.

What gauge of wire will I need and what size of conduit will I need to run it underground?

Thank you,
Buddy1

Use 3-#250 MCM XHHW and 1#2 XHHW in 3 " PVC Sch 40 PVC conduit.

Are you sure a 250 amp breaker in a 500 amp panel? Very odd size.