Understanding Metric Tire Measurements
Understanding Metric Tire Measurements
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" |
Example: 225/70R15
225 | = Section width in millimeters |
70 | = Aspect ratio (ratio of section height to section width) |
15 | = Rim diameter |
R | = Radial Construction B = Bias Construction D = Bias Belted Construction |


Metric Tire Measurement
To calculate:
Tire Width: | Section width divided by 25.4 (Ex: 225 / 25.4 = 8.86") |
Section Height: | Tire width times aspect ratio (Ex: 8.86" x 70% = 6.20") |
Overall Diameter: | Section height times 2 plus rim diameter (Ex: (6.20" x 2) + 15 = 27.40") |
.jpg)