My data inputs would look like this:
|Original Tires||265 MM||65 Percent||17 Inches|
|New Tires||245 MM||45 Percent||17 Inches|
Input Your Data In the "AnyCalculator" Tire Size Calculator Below. (Estimate Of Actual Speed ONLY!)
This calculator is designed for information related to tire size changes and the impact they have on the calibration and accuracy of a speedometer. It determines speedometer error at different speeds using tire size information based on published tire dimensions as given by the standard US tire system (i.e. 205/45-ZR16). All calculations are based on the assumption of a new tire (as opposed to a used tire) where the numbers on the tire accurately represent the dimensions.
Tire width - Also called the tread width, this is the width of your tire's treaded area, measured in millimeters. Typically, this will be a high number that is displayed first on a tire.
Aspect ratio - Also called the profile, this number is a percentage. Usually the second number displayed on a tire, this is the sidewall height divided by the section width.
Wheel diameter - This number refers to the rim size of your vehicle's wheel. It's usually measured in inches.
When purchasing new tires for your car or truck, it's always a good idea to stay within the limits set by your vehicle's manufacturer. Different tire sizes can affect many of the systems in your vehicle.
The answers to your calculations are only an estimate and should be verified by traffic accident experts if you were in an accident. The estimate by accident experts will be different and more accurate that any online calculator. Do not rely on this online calculation only, it is just an estimate example.