Diameter-matched size
Solves the aspect ratio that holds overall diameter constant on the new rim.
Plus sizing
Plus-size a wheel without changing diameter.
Enter your current size and a new rim diameter to find the tire that keeps overall height the same.
In short
Solves the tire size that keeps overall diameter constant when moving to a larger or smaller rim.
- Keeping diameter constant preserves speedometer, ABS, and gearing calibration.
- Rounds the aspect ratio to a manufactured step and validates the resulting size.
What it does
How this tool helps.
Calibration safe
Keeping diameter the same keeps the speedometer, odometer, and gearing accurate.
Real sizes only
Rounds the aspect ratio to a manufactured step and checks the result is a valid size.