front backspacing

I've got 245/60r14s on now, which seems to be the same diameter, but 1" wider than a 225/60r15. So just curious if the backspacing would still be off with the narrower tires. Also, I can get the wheels I'm wanting in a 15x6, which should work with the 225/60r15s, but they too have the same 3.75 backspacing. So would the 6" rims work? I am by no means a wheels and tires guy, so excuse the learning curve...lol