Assuming you have a good supply voltage at the panel board in your shop you would have to have really long runs to be worried about voltage drop. If you are really interested the NEC national electric code has guidance on calculations for this. Also the NEC provides for the wire size vs breaker size. My house is single story and about 100 ft long. I used 14 awg copper for all lighting and 12 awg for all receptacles. There is virtually no voltage drop at my longest run. I work for UL and only once in a Costco store did I have excessive voltage drop that affected my test. Sure it is possible but call your utility. Voltages have been increased over the years. Some people may remember 110 V. 120v is typical now. If you are in Canada the power runs are long and Canadian motor equipment must pass a test at 104v. One other important thing on wire size circuits are only supposed to be run at 80% capacity. So a saw that draws 16amps on a 20 amp circuit is fine. A saw that draws 18 amps on a 20 amp circuit should really be on a 25-30 amp circuit/10 awg copper. There is much more to all this. I have 5 large woodworking tools. I run all these 240/20amp. The motor runs cooler. So I have 5 240v circuits and 10 120v circuits. I install two 240v cord drops and wish I had installed 120 v cord drops too. I wish I had installed 1 50 amp circuit for a large welder. Some day. Interesting reading different thoughts. The more circuits the better its all about cost. As far as main breaker its hard for me to see an amature home shop use 200amps at one time. Even welding and a compressor running would not even be close.
