TreadSize

Fitment comparison bench

Compare two tire sizes

Enter the OE stock size and a replacement size to see the diameter difference, visual overlay, speedometer error, ±3% safety check, and fitment risk notes.

Garage tire stack with a TreadSize overlay comparing stock and replacement tire diameters
Fitment warning: the 3% diameter rule is only the first gate. Real clearance also depends on wheel offset, rim width, suspension travel, steering lock, load index, and speed rating.
Start from the vehicle's OE size. The stock field should match the door placard or owner's manual, not just the tire currently on the car.
OE size entry

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