We have taken all the hard work out of calculating wheel and tyre fitments, enabling you to quickly compare an original fitment/size against a proposed fitment/size.
There are other tools like this out there, but our calculator is the only one (to our knowledge) based on actual physical wheel/tyre measurements as opposed to what are called "nominal" measurements. Nominal measurements are good to a point but aimed at manufacturing standards rather than fitment comparisons, so aren't the same as the physical measurements and therefore no where near as accurate in real-life. This makes our calculator the world's most accurate!
For example; a wheel measuring 8.5" in width is actually physically 240mm. Also a tyre measuring 225 in width, is actually physically 235mm.
There can be minor fluctuations between manufacturers, but this is as close as you'll ever get it.
Our calculator will give you all aspects of how the fitments differ, and you can play with this infinitely to perfect your new wheel/tyre fitment.
at 30.00 mph
at 40.00 mph
at 50.00 mph
at 60.00 mph
at 70.00 mph
Visual Illustration
Existing
Proposed
DISCLAIMER: This tool is intended as an aid and we accept no liability for any issues and consequences that may arise, and we always recommend taking your own measurements and making your own calculations on the vehicle with the physical products. Our tool doesn't take into consideration brake, steering or suspension components.