Original and Aftermarket Tire Size Calculator
Default entries or for example only and should be typed over.
Example 235/75R16
235=Tire Width 75=Aspect Ratio 16=Rim Diameter
Enter Original Size Tire
Enter Alternate Size Tire
Tire Width in (mm)
Tire Width in (mm)
Aspect Ratio
Aspect Ratio
Rim Diameter in (inches)
Rim Diameter in (inches)
Foundation Speedometer Reading
MPH
Calculated Comparison Results
Original Tire
Alternate After Market Tire
Side Wall Height (inches)
Side Wall Height (inches)
Tire Width (inches)
Tire Width (inches)
Tire Diameter (inches)
Tire Diameter (inches)
Tire+Wheel Radius (inches)
Tire+Wheel Radius (inches)
Tire Circumference (inches)
Tire Circumference (inches)
Tire Circumference (inches)
% Difference
Revolutions per mile
Revolutions per mile
Revolutions per kilometer
Revolutions per kilometer
When actually driving (MPH)
The speedometer will read (MPH)