Tire size converter (mm ↔ inches)
What is this tire size in inches?
Convert a tire size between millimetres and inches: a metric size such as 285/75R16 has an overall diameter of about 834 mm (32.8 in) and is 285 mm (11.2 in) wide, while a flotation size like 33x12.50R15 is 33 inches (838 mm) tall. This converter shows overall diameter, section width, sidewall height and circumference in both units.
| mm | in | |
|---|---|---|
| Diameter | 834 | 32.83 |
| Width | 285 | 11.22 |
| Sidewall | 214 | 8.42 |
| Circumference | 2,620 | 103.14 |
Convert a tire size between millimetres and inches: a metric size such as 285/75R16 has an overall diameter of about 834 mm (32.8 in) and is 285 mm (11.2 in) wide, while a flotation size like 33x12.50R15 is 33 inches (838 mm) tall. This converter shows overall diameter, section width, sidewall height and circumference in both units.
Computed from the nominal size; actual fitted dimensions vary slightly with rim width.
Worked examples
Metric and flotation markings look different, but the table is calculated from the same nominal diameter, width and rim-size rules.
| Size | Overall diameter | Section width | Sidewall | Circumference |
|---|---|---|---|---|
| 225/45R17 | 24.97 in / 634 mm | 8.86 in / 225 mm | 3.99 in / 101.3 mm | 78.45 in / 1993 mm |
| 285/75R16 | 32.83 in / 834 mm | 11.22 in / 285 mm | 8.42 in / 213.8 mm | 103.14 in / 2620 mm |
| 33x12.50R15 | 33.00 in / 838 mm | 12.50 in / 318 mm | 9.00 in / 228.6 mm | 103.67 in / 2633 mm |
What to do with it: Round marketing sizes can hide several millimetres of difference.
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- Content updated
- 2026-06-23
What changed
- Checked generated routes, metadata, sitemap inclusion and localized page rendering.