The Wheel Fitment, Tyre Stretch, Rolling Radius and Speedometer Error Calculator

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
634.5mm
631.9mm
Circumference
1993.3mm
1985.2mm
Poke
90.6mm
23.9mm
Inset
112.6mm
153.9mm
Speedo error
0%
0.41%
Reading at 30mph
30mph
30.12mph
Reading at 60mph
60mph
60.25mph
Ride height gain
0mm
-1.3mm
Arch gap loss
0mm
-1.3mm
Wheel Fitment Guide

Compared to your existing wheel, this new wheel will have an inner rim which is 41.3mm closer to the suspension strut. The outer rim will poke out 66.7mm 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.

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16x7 ET65 wheel options
WORK Wheels
SSR Wheels
JR Wheels
Rotiform Wheels
Rota Wheels
Bola Wheels
Fuel Wheels
3SDM
Concaver
7Twenty
BBS
1Form
Niche
Autostar
Dare
Motegi
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