Standard to Metric Farm Tire Size Conversion Chart
We often hear from customers who are converting from bias ply tractor tires to radial tractor tires that they are confused about which size their equipment takes. This can also occur when converting from a standard size radial farm tractor tire to a metric farm tractor tire. Some manufacturers list both tire sizes on their tires and others simply use the metric size. Ho matter what, the chart below will help you in finding the right radial size or metric size for your tractor or other farm equipment.
Many times when converting from a bias ply farm tire to a radial farm tire is necessary to convert from the standard tire size to the metric tire size. Below is a chart of standard farm tire sizes and their metric equivalent.
Standard Size | Radial Size | Metric Size |
11.2x20 | 11.2R20 | 280/85R20 |
12.4x20 | 12.4R20 | 320/85R20 |
9.5x24 | 9.5R24 | 250/85R24 |
11.2x24 | 11.2R24 | 280/85R24 |
12.4x24 | 12.4R24 | 320/85R24 |
13.6x24 | 13.6R24 | 340/85R24 |
14.9x24 | 14.9R24 | 380/85R24 |
16.9x24 | 16.9R24 | 420/85R24 |
18.4x26 | 18.4R26 | 420/85R26 |
11.2x28 | 11.2R28 | 280/85R28 |
12.4x28 | 12.4R28 | 320/85R28 |
13.6x28 | 13.6R28 | 340/85R28 |
14.9x28 | 14.9R28 | 380/85R28 |
16.9x28 | 16.9R28 | 420/85R28 |
14.9x30 | 14.9R30 | 380/85R30 |
16.9x30 | 16.9R30 | 420/85R30 420/90R30 |
18.4x30 | 18.4R30 | 460/85R30 |
12.4x32 | 12.4R32 | 320/85R32 |
12.4x34 | 12.4R34 | 320/85R34 |
14.9x34 | 14.9R34 | 380/85R34 |
16.9x34 | 16.9R34 | 420/85R34 |
18.4x34 | 18.4R34 | 460/85R34 |
20.8x34 | 20.8R34 | 520/85R34 |
12.4x36 | 12.4R36 | 320/85R36 |
13.6x36 | 13.6R36 | 340/85R36 |
13.6x38 | 13.6R38 | 340/85R38 |
14.9x38 | 14.9R38 | 380/85R38 |
16.9x38 | 16.9R38 | 420/85R38 |
18.4x38 | 18.4R38 | 460/85R38 |
20.8x38 | 20.8R38 | 520/85R38 |
18.4x42 | 18.4R42 | 460/85R42 |
20.8x42 | 20.8R42 | 520/85R42 |
20.8x46 | 20.8R46 | 520/85R46 |
Using this chart you should be able to convert your standard tire size to its metric size.