Tire size change calculator

Use the calculator to see what happens to your speedometer reading when you change the size of your tires and wheels. The graphic shows your stock tire selection in an outline overlayed on your new tire selection.  This calculator is supplied thanks to our friends at

This calculator gives various tire measurements from standard tire size specifications. It will give several dimensions for the tires listed in both fields below. The output will also show the tire specs given in the "Tires to compare" field as a percentage difference from the tire spec in the "Stock size" field. 

Units: English Metric
Stock size:
Tires to compare:
Note: You may enter multiple tire specifications in the "Tires to Compare" box. The resulting output will be a table comparing all sizes to the stock size.
Example: 195/55-14, 205/50-15

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