Tire Size Converter — Metric to Inches & Flotation
Convert any tire size to inches: overall diameter, width and sidewall. Works both ways — metric sizes like 285/70R17 and flotation sizes like 33x12.50R17 — and shows which other sizes share (almost) the same diameter.
Size to convert
Sizes with (almost) the same diameter
Width is the first number of the size code — a 285 tire is 285 mm, about 11.2 inches, across.
Tire size conversion chart
Every common size below is computed with the same formula — diameter, width and sidewall in inches.
| Size | Diameter (in) | Width (in) | Sidewall (in) | Revs / mile |
|---|---|---|---|---|
| 205/55R16 | 24.88 | 8.07 | 4.44 | 811 |
| 215/60R16 | 26.16 | 8.46 | 5.08 | 771 |
| 225/45R17 | 24.97 | 8.86 | 3.99 | 808 |
| 235/45R17 | 25.33 | 9.25 | 4.16 | 796 |
| 225/65R17 | 28.52 | 8.86 | 5.76 | 707 |
| 235/65R17 | 29.03 | 9.25 | 6.01 | 695 |
| 245/65R17 | 29.54 | 9.65 | 6.27 | 683 |
| 265/65R17 | 30.56 | 10.43 | 6.78 | 660 |
| 235/75R15 | 28.88 | 9.25 | 6.94 | 698 |
| 31x10.50R15 | 31 | 10.5 | 8 | 651 |
| 33x12.50R15 | 33 | 12.5 | 9 | 611 |
| 245/70R16 | 29.5 | 9.65 | 6.75 | 684 |
| 265/70R16 | 30.61 | 10.43 | 7.3 | 659 |
| 245/75R16 | 30.47 | 9.65 | 7.23 | 662 |
| 265/75R16 | 31.65 | 10.43 | 7.82 | 637 |
| 285/75R16 | 32.83 | 11.22 | 8.42 | 614 |
| 315/75R16 | 34.6 | 12.4 | 9.3 | 583 |
| 235/85R16 | 31.73 | 9.25 | 7.86 | 636 |
| 245/70R17 | 30.5 | 9.65 | 6.75 | 661 |
| 255/70R17 | 31.06 | 10.04 | 7.03 | 649 |
| 265/70R17 | 31.61 | 10.43 | 7.3 | 638 |
| 275/70R17 | 32.16 | 10.83 | 7.58 | 627 |
| 285/70R17 | 32.71 | 11.22 | 7.85 | 617 |
| 315/70R17 | 34.36 | 12.4 | 8.68 | 587 |
| 33x12.50R17 | 33 | 12.5 | 8 | 611 |
| 35x12.50R17 | 35 | 12.5 | 9 | 576 |
| 37x12.50R17 | 37 | 12.5 | 10 | 545 |
| 265/60R18 | 30.52 | 10.43 | 6.26 | 661 |
| 265/65R18 | 31.56 | 10.43 | 6.78 | 639 |
| 275/65R18 | 32.07 | 10.83 | 7.04 | 629 |
| 285/65R18 | 32.59 | 11.22 | 7.29 | 619 |
| 275/70R18 | 33.16 | 10.83 | 7.58 | 608 |
| 33x12.50R18 | 33 | 12.5 | 7.5 | 611 |
| 35x12.50R18 | 35 | 12.5 | 8.5 | 576 |
| 265/50R20 | 30.43 | 10.43 | 5.22 | 663 |
| 275/55R20 | 31.91 | 10.83 | 5.95 | 632 |
| 285/55R20 | 32.34 | 11.22 | 6.17 | 624 |
| 275/60R20 | 32.99 | 10.83 | 6.5 | 611 |
| 33x12.50R20 | 33 | 12.5 | 6.5 | 611 |
| 35x12.50R20 | 35 | 12.5 | 7.5 | 576 |
| 285/45R22 | 32.1 | 11.22 | 5.05 | 628 |
| 305/40R22 | 31.61 | 12.01 | 4.8 | 638 |
What is a 285/70R17 in inches?
A 285/70R17 works out to 32.71" tall and 11.22" wide — roughly a 33-inch class tire, but not identical to a 33x12.50R17 flotation tire, which is a true 33.0" tall and 12.5" wide.
What metric size equals a 33-inch tire?
There is no single exact match — the closest common metric sizes to 33.0" are 285/70R17 (32.71") and 275/60R20 (32.99"). The converter above lists near-matches for any size you enter.
Why do two "same size" tires measure differently?
The size code is nominal. Tread depth, casing design and load change the real measured diameter by a few tenths of an inch between brands. The formula values here are the neutral reference every size is compared on.