It's fairly easy on the conversion but outside diameter is dependent upon the manufacturer. Finally a non-mechanical expertise question <img src="/forums/images/graemlins/smile.gif" alt="" />

285 is the width in millimeters and there are 25.4mm to the inch.
75 is a ratio indicating that the sidewall height is 75% of the total width of the tire.

So 285 divided by 25.4 = the width in inches = 11.2205"

and 75% of 11.2205" would be the sidewall height = 8.4154"

The overall height of the tire (Diameter) would then be 8.4154"(sidewall 1) + 16"(wheel height) + 8.4154" (sidewall 2) = 32.8307"

This is in theory and is purely based upon math and not the variation of manufacturing. Brew <img src="/forums/images/graemlins/cheers.gif" alt="" />

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