Compared to your existing wheel, this new wheel will have an inner rim which is 11.7mm further away from the suspension strut. The outer rim will poke out 13.7mm less than before.
The strut shown in the diagram is for show only. Don't worry if the wheel looks like it fouls!
Bear in mind most tyre manufacturers vary slighty from the specs, and that it could be dangerous to run tyres on wheels they aren't designed to fit.
Will They Fit - The No.1 Online Alloy Wheel & Tyre Fitment Calculator
Use our comprehensive online wheel size calculator to visualise different alloy wheels and tyre combinations. Calculate your offset, compare tyre stretch, rolling radius and more. Compare your new and existing setup and our tool will show you key measurements for accurate wheel and tyre fitment.