found this and thought I would post it up for posterity sake - maybe sticky or wiki?

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Metric to Imperial tire conversion chart
Metric = Imperial Metric = Imperial Metric = Imperial
215/75/15 27.7"x 8.5" 245/75/16 30.5"x 9.6" 315/70/17 34.9"x 12.9"
225/70/15 27.4"x 8.9" 255/70/16 30.0"x 10.0" 275/65/18 32.1"x 11.0"
225/75/15 28.3"x 8.9" 265/70/16 30.6"x 10.4" 375/50/18 33.0"x 15.4"
235/75/15 29.0"x 9.3" 265/75/16 31.6"x 10.4" 325/60/18 33.2"x 13.3"
245/75/15 29.5"x 9.6" 275/70/16 31.2"x 10.8" 325/65/18 34.8"x 13.5"

255/75/15 30.0"x 10.0" 285/75/16 32.8"x 11.2" 305/70/18 35.0"x 12.2"
265/75/15 30.6"x 10.4" 295/75/16 33.4"x 11.6" 375/60/18 35.7"x 15.5"
205/85/16 29.7"x 8.1" 305/70/16 33.0"x 12.2" 395/65/18 37.8"x 15.7"
215/75/16 28.7"x 8.5" 315/75/16 34.8"x 12.9" 325/50/20 33.0"x 13.2"

225/70/16 28.4"x 8.9" 375/55/16 32.8"x 15.5"
225/75/16 29.2"x 8.9" 395/70/16 37.9"x 16.0"

235/70/16 29.0"x 9.3" 245/70/17 30.6"x 9.8"
235/85/16 31.7"x 9.3" 265/70/17 31.6"x 10.7"
245/70/16 29.5"x 9.6" 285/70/17 33.0"x 11.5"