285/70R17 tire size in inches and millimeters
285/70R17 measures 32.71 inches in overall diameter, 11.22 inches in section width, with a 7.85 inch sidewall.
Every dimension
| Size | In inches | In millimetres |
|---|---|---|
| Overall diameter | 32.71 in | 830.8 mm |
| Section width | 11.22 in | 285 mm |
| Sidewall height | 7.85 in | 199.5 mm |
| Circumference | 102.76 in | 2,610.0 mm |
| Revolutions per mile | 616.6 per mile | 383.1 per km |
Sizes that fit the same wheel
These sizes share a 17 inch wheel diameter and sit within 3% of 285/70R17 in overall diameter, which is the range a swap stays inside without recalibrating anything.
The percentage difference in overall diameter is the speedometer error: a tire 2% taller makes an indicated 60 mph a true 61.2 mph. They are the same number, so it is shown once.
| Alternate size | Overall diameter | Difference (in) | Difference (%) | Width difference (in) |
|---|---|---|---|---|
| 235/85R17 | 32.73 | 0.02 | 0.06 | -1.97 |
| 265/75R17 | 32.65 | -0.06 | -0.18 | -0.79 |
| 305/65R17 | 32.61 | -0.10 | -0.30 | 0.79 |
| 335/60R17 | 32.83 | 0.12 | 0.36 | 1.97 |
| 245/80R17 | 32.43 | -0.28 | -0.84 | -1.57 |
| 355/55R17 | 32.37 | -0.33 | -1.02 | 2.76 |
| 255/80R17 | 33.06 | 0.35 | 1.08 | -1.18 |
| 325/60R17 | 32.35 | -0.35 | -1.08 | 1.57 |
| 315/65R17 | 33.12 | 0.41 | 1.26 | 1.18 |
| 275/75R17 | 33.24 | 0.53 | 1.62 | -0.39 |
| 275/70R17 | 32.16 | -0.55 | -1.69 | -0.39 |
| 295/70R17 | 33.26 | 0.55 | 1.69 | 0.39 |
| 345/60R17 | 33.30 | 0.59 | 1.81 | 2.36 |
| 295/65R17 | 32.10 | -0.61 | -1.87 | 0.39 |
| 225/85R17 | 32.06 | -0.65 | -1.99 | -2.36 |
| 255/75R17 | 32.06 | -0.65 | -1.99 | -1.18 |
| 245/85R17 | 33.40 | 0.69 | 2.11 | -1.57 |
| 345/55R17 | 31.94 | -0.77 | -2.35 | 2.36 |
| 315/60R17 | 31.88 | -0.83 | -2.53 | 1.18 |
| 235/80R17 | 31.80 | -0.91 | -2.77 | -1.97 |
| 325/65R17 | 33.63 | 0.93 | 2.83 | 1.57 |
How this is worked out
sidewall height in millimetres = section width × aspect ratio ÷ 100
overall diameter in inches = wheel diameter + (section width × aspect ratio × 2) ÷ 2540
section width in inches = section width in millimetres ÷ 25.4
circumference in inches = π × overall diameter
revolutions per mile = 63360 ÷ circumference in inches
The divisor is 2540, not the 2550 some converters publish. Two sidewalls in inches are 2 × width × aspect ÷ (100 × 25.4), and the rounding costs about 0.07 inches at 34 inches.
For 285/70R17: the sidewall is 199.5 millimetres, two of them are 15.71 inches, and adding the 17 inch wheel gives 32.71 inches overall.
Questions
What size is 285/70R17 in inches?
32.71 inches in overall diameter, 11.22 inches in section width, with a 7.85 inch sidewall.
How tall is a 285/70R17 tire?
32.71 inches, which is 830.8 millimetres.
What do the numbers in 285/70R17 mean?
285 is the section width in millimetres, 70 is the sidewall height as a percentage of that width, and 17 is the wheel diameter in inches. Overall diameter is the wheel diameter plus two sidewalls: 32.71 inches.
Does 285/70R17 fit a 17-inch wheel?
Yes — the 17 in a metric tire size *is* the wheel diameter, so 285/70R17 is made for a 17 inch wheel. Rim width is a separate question the sidewall code does not answer.
What tire sizes are equivalent to 285/70R17?
235/85R17, 265/75R17, 305/65R17 are the closest by overall diameter, all on the same 17 inch wheel.
Fitting a size is not only a matter of diameter. Rim width, load rating, speed rating and clearance all decide whether a size works on a given vehicle, and none of them can be read off the sidewall code alone.