Originally Posted by
John K Jordan
I have another take on this, perhaps from my tendency to over-engineer things. If I'm going to the effort of running wires in the walls for and ceiling for a 240v circuit to a power tool and #12 is sufficient, I will usually run #10 instead. That gives me flexibility in the future to use that circuit for a larger load with a larger breaker. In fact, I generally just install the larger breaker at the time I run the wire or make a note to my future self in the panel.
The extra cost is insignificant compared to the installation effort. #10 is harder to work with but after working with #1, 4, 6, and 8 everything else is easy.
JKJ