Insert your existing wheel and tyre specs, and the desired size, and the outcome is shown on the diagram.

Your existing setup

Existing Tyre
Existing Wheel

Your new setup

New Tyre
New Wheel
Your Results

Existing

New

Diameter
668.7mm
641.7mm
Circumference
2100.8mm
2016mm
Poke
57.6mm
66.9mm
Inset
145.6mm
110.9mm
Speedo error
0%
4.21%
Reading at 30mph
30mph
31.26mph
Reading at 60mph
60mph
62.52mph
Ride height gain
0mm
-13.5mm
Arch gap loss
0mm
-13.5mm
Wheel Fitment Guide

Compared to your existing wheel, this new wheel will have an inner rim which is 34.7mm further away from the suspension strut. The outer rim will poke out 9.3mm more 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.