The ETyreStore Tyre Calculator is designed to make swapping to Alternate and Equivalent Sizes easy. This is the only calculator (that we are aware of) that can calculate the difference between Metric, Imperial and Truck Tyre Sizing Specifications. It factors basic vehicle weight into the calculatoin as well as tyres lose a small amount overall diameter depending on the weight of the vehicle (think about how the height of your car goes down when a tyre is flat). Unfortunately many incorrectly believe that tyres are pieces of steel (rather than rubber) and measurements are exact - they aren't. Even the same product from teh same manufacturer produced on the same production line can vary slightly in measurements if it was stored differently (E.g. at the bottom of a stack versus the top of a stack, or sideways versus horzizontally..). Additionally while putting the new tyre next to your vehicle prior to installation may give a version of a visual representation, it will be completely different (usually a lot smaller in overall diameter), once it is fitted to the vehicle, so always complete a full fitment check (tyre fitted to the vehicle) to be sure a tyre is going to work for you.
Have a play with the calculator below, hopefully it helps you out, included at the bottom of this page is a visual representation showing the differences between Metric, Imperial and Truck Tyre Sizes.
Please input details below of both the Current Tyre Size on your vehicle and the New Tyre Size.
Current Tyre Size
Tyre Size Type
Metric
Imperial
Truck
Width (mm)
Profile (%)
Rim (Inch)
/
R
Overall Diameter*:
Rolling Circumference:
Tyre Width:
Sidewall Height:
*Tyres can differ by up to 5% depending on manufacturer, tread type and pre-fit storage.
New Tyre Size
Tyre Size Type
Metric
Imperial
Truck
Width (mm)
Profile (%)
Rim (Inch)
/
R
Overall Diameter*:
Rolling Circumference:
Tyre Width:
Sidewall Height:
*Tyres can differ by up to 5% depending on manufacturer, tread type and pre-fit storage.
Tyre Difference Calculations
Overall Diameter Difference:
Overall Diameter Percentage Difference:
Circumference Difference:
Circumference Percentage Difference:
Width Difference:
Width Percentage Difference:
Sidewall Height Difference:
Sidewall Percentage Difference:
Actual Speed at Indicated 100 Klms/H:
The Above Calculations can swing by up to 10% depending on manufacturer, tread type and pre-fit storage.
