Fitting worksheet
A shortlist in one table: every candidate size against the stock size, with the diameter difference, the axle height change and the speedometer effect worked out.
Loading your worksheets.
What is free here
Every size page, the size decoder, the comparison tool, the load index table, the speed symbol table and every marking reference stay free forever, with no account and no limit.
On this page a free worksheet holds 3 lines and keeps 1 saved sheet. Premium removes the line limit, keeps one worksheet per vehicle, prints the sheet and exports it as CSV. The numbers a free worksheet computes are identical to the ones a paid one computes - the volume and the output format are what differ, never the figures.
Before you fit anything
SidewallRef calculates the dimensions a size code implies and reproduces the published load index and speed symbol tables. It does not know your vehicle.
Load index and speed rating must meet or exceed what the vehicle placard specifies. The placard is in the driver's door jamb on most vehicles and is the authority for your vehicle, not this site.
Clearance at full lock and full suspension travel, wheel width and offset, brake and suspension component clearance, axle load capacity, inflation pressure and any legal requirement where you drive are the owner's and the fitter's responsibility.
Nothing here approves a fitment. Confirm any change with a qualified tire fitter and with the vehicle manufacturer's own specification before driving on it.