# Tire size conversion question?

Discussion in 'The Garage' started by mattman4x4, Nov 1, 2005.

1. ### mattman4x41/2 ton status

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How large of a tire is a p 265/75/R16? How do I convert that to inches? is it a 31 inch, 30 inch, and if so what dose 31 or 30 inches mean? Is it the diameter of the total tire, or is it the tire with out the rim?

Thanks!

2. ### cegusman3/4 ton status

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3. ### guido6661/2 ton status

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Metric tires are measured in millimeters. 25.4mm = 1". Metric tire sizes are <tread width>/<sidewall percentage of tread width>/<R for radial><rim diameter>

So tread width is 265mm / 25.4mm = 10.433"
The sidewall is 10.433" x 0.75 (which is 75%) = 7.82"
That is the size of one sidewall, so to get overall tire size multiply by 2 (since you have one sidewall on each side of the rim) and add the rim size.
Tire diameter = 7.82" x 2 + 16 = 31.64"

Now sizes differer from ideal, but this will give you an idea of what size it SHOULD be.

So this is a 31.64x10.43R16 in standard measure.

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