I am going to be working on a project where I would like to put in a 100 AMP sub panel in an out building. I have a long run so I need to take voltage drop into consideration (185 ft.). When I look at voltage drop calculators, one of the variables is always volts. I would like to clear up a spot of confusion for me so I do not choose the wrong size wire for the run. The panel would have 240v capability, but the circuits from the panel may be 120v breakers or 240v 2 post breakers. So to calculate voltage drop between my main panel and my new subpanel, do I use 120v or 240v for the calculation?