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How to choose the right tire.

Here are some simple formulas to help you decide which tire size to use.

Here are the formulas with some examples:

1.Section width: To convert from millimeters to inches, multiply the given mm by .03937, For example the stock section width of a WS6 tire is 225 mm's So 225x.03937=8.86 inches. The section width is the widest point of the tire, not patch.

2. Section height: First you need to find sidewall height. This is done by dividing the section width by 25.4: 225/25.4=8.858 inches.

Then multiply the overall sidewall height by the aspect ratio: 8.858x.70=6.2 inches.

Then to get overall size multiply the sidewall height by 2 (top and bottom) and add rim diameter: 6.2x2+15"= 27.4 inches.

So let's plug in some others.


255/25.4=10.04 inches.

10.04x.60=6.02 inches

6.02x2+15=27.04 inches overall tire height.




5.79x2+15=26.58 inches




5.6x2+15=26.2 inches

Here is the 235/60 15 on my T/A


Here is the 255/60 15 on my T/A




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