Tyre Checker & Equivalence Ratings

Use our free tool to ensure your current tyres are compliant,
or to confirm equivalent legal sizes

Tyre Equivalence Checker

Enter the standard tyre size from the vehicle sticker or handbook. You can also enter the tyre currently fitted to compare it. This tool checks the dimensional variance in overall diameter and shows practical equivalent sizes within ±3%.

Accepted sizes shown below are dimensionally equivalent only. Load index, speed rating, wheel suitability and vehicle clearance still need to be checked separately.
Standard size
Current fitted size
Standard diameter
Current diameter
Variance
Allowed range±3.00%
Rolling circumference
Accepted sizes shown
Accepted size Variance Wheel Width change
Showing practical sizes first. Wheel options are generated up to 23" and shown only when a matching equivalent size exists.

How it works

For a tyre size to be considered equivalent, the overall diameter can be up to 3% smaller or up to 3% larger than the original size.

That means a tyre is normally acceptable if it falls anywhere between -3% and +3% variance from the standard tyre size.

Important

The replacement tyre must also meet or exceed the original minimum load index and speed rating.

Example: if the original tyre is 225/45 R17 91W, any equivalent replacement must still have at least a 91 load index and a W speed rating. So...

✅ A tyre marked 225/45 R17 94W would be acceptable because the load rating is higher and the speed rating is the same
✅ A tyre marked 225/45 R17 91Y would also be acceptable because the load rating is the same and the speed rating is higher
❌ A tyre marked 225/45 R17 88W would not be acceptable because the load index is too low
❌ A tyre marked 225/45 R17 91V would not be acceptable because the speed rating is too low

This checker reads sizes like 225/45 R17, 225/45R17 or 225-45-17. It does not currently validate load index or speed rating, so those still need to be checked separately.