Need help, what size rim is this?

[rays-64]

The photo is from my notch. The rim is from Porsche Boxster and are sitting on 205/55/16 tires. The fronts have a ET50 and the rears are ET40.
Measuring the actual rim from outer most edge to outer most edge (with the tire installed) the front rims are 7" wide with the tire measuring 8" wide and the rears are 8" wide with the tire measuring 8 1/2" wide.

looking on the inside of the rim, there are possible item numbers along with the ET size. the item numbers dont state any rim size.

Looking for the exact size of these becasue I am planning on changing the rims and tires and trying to figure out where the car might sit after installing new wheels. Or is it best to take to a tire shop so they can dismount rim from tire to get the exact size.

thanks for any help