TyreRack

Use our tyre size calculator to calculate the diameter, width, sidewall, circumference, and revolutions per mile of any tyre. Just type in a metric or standard size tyre and click calculate.

The tyre size comparison calculator takes the measurements of two tyres and compares the diameter, width, sidewall, circumference, and revolutions per mile. Then as a bonus it shows examples of your speedometer reading with the first tyre, and the actual speed you're traveling if you were to install the second tyre. A very useful tyre calculator when searching for tyres that are a different size then stock.

Another tyre size calculator we have is our speedometer correction calculator. This is valuable if you plan to or are already running bigger tyres then stock, and want to know the speed you are actually traveling compared to you're speedometer reading. A bigger tyre has a larger circumference, thus traveling a further distance for each revolution. A speedometer reads the amount of revolutions your tyres are making, not how far you are traveling. Therefore you are actually traveling faster then your speedometer says when you have larger tyres then stock, and slower then you're speedometer says if you have smaller tyres.