A mod should be able to change it for you if they spot this.
Also just type power supply calculator into google.
As an aside, what is your build for? Becuase currently it looks overkill if it's for gaming. Unless you're doing music production you don't need the sound card either.
Drop to an i5, 8gb of RAM and get an SSD.
Also if you're OC'ing you'll want a decent cooler, if not you dont need a K series CPU and dont need a Z77 mobo.