Power supply questions?

-if i buy a 750w power supply and my computer only uses 500w will my bill at the end of the month be for 700 or 500Your computer will only use what it needs in order to run, if you start adding equipment however, it will require more and more power.No. But you can use those extra 200wattt to power up a blender or a juicer.
Your computer will only use what it needs.