Lexus RX400H Wheel Width Confusion

[montyjohn]

I'm trying to replace my alloys on an RX400h as they are corroded with either some aftermarket or off another car.
I'm trying to establish what width I need and I'm getting a bit confused.

All the online specs say that my 18" wheel as fitted with 235mm wide tyres is 7" wide.
Example: https://www.wheel-size.com/size/lexus/rx/2006/

This contradicts the tyre width vs wheel width table here:
https://www.tyres-pneus-online.co.uk/tyre-equivale...
The above link suggests I should have a 8" to 8.5" wheel.

I've tried measuring the width, with the tyre on which is a little tricky. I measure the outside alloy rim width to be slightly under 8.5".

Based on the above, can anyone advise wheel wheel width I need?