285/70R17 Tire Size
285/70R17 diameter, sidewall, revolutions per mile, and plus-sizing options.
The 285/70R17 tire size breaks down as: 285 mm section width, 70% aspect ratio, and a 17-inch rim. Below are its real, calculated dimensions.
285/70R17 Calculated Dimensions
| Metric | Value |
|---|---|
| Overall diameter | 32.7 in (831 mm) |
| Sidewall height | 7.9 in (200 mm) |
| Circumference | 102.8 in (2610 mm) |
| Revolutions per mile | 617 |
Typical Fitment
285/70R17 is most often found on off-road SUVs and trucks. Always confirm against the door-jamb placard or owner manual before fitting.
Plus-Sizing Alternatives
These sizes keep the overall diameter close to 285/70R17, so speedometer and gearing stay near stock:
| Size | Diameter | Diameter change |
|---|---|---|
| 295/70R17 | 33.26 in | +1.7% |
| 295/65R18 | 33.10 in | +1.2% |
| 305/55R19 | 32.21 in | -1.5% |
Speedometer Note
If you fit a 295/70R17 instead of 285/70R17, the diameter changes by +1.7%. A taller tire makes your speedometer read low — at a true 60 mph it would show roughly 59 mph. A shorter tire has the opposite effect, so the gauge reads high.
Use the tire calculator to compare 285/70R17 against any other size and see the exact diameter and speedometer difference.
Frequently Asked Questions
What does 285/70R17 mean?
285/70R17 means a 285 mm wide tire with a 70% sidewall aspect ratio mounted on a 17-inch rim. The aspect ratio is the sidewall height as a percentage of the width.
Can I plus-size from 285/70R17?
Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 285/70R17 are 295/70R17, 295/65R18, 305/55R19.
Will 285/70R17 affect my speedometer?
Only if it differs in diameter from your original size. A taller tire reads low; a shorter tire reads high. Compare the two sizes with the calculator to find the percentage.