What wheel size fits a 215/45/17? Is it 17x7 or 17x7.5?

At tirerack.com, I selected a wheel that was 17x7 then selected a tire that was 215/45/17 which was a suggested tire size. But at the checkout screen it tells me that the tire's diameter did not match the wheel size. confused

I'm so confused.

K&N Drop in Filter
I don't know anything under the hood smirk