31x10.5R15 Tire Size
31x10.5R15 diameter, sidewall, revolutions per mile, and plus-sizing options.
The 31x10.5R15 tire size breaks down as: 267 mm section width, 76% aspect ratio, and a 15-inch rim. Below are its real, calculated dimensions.
31x10.5R15 Calculated Dimensions
| Metric | Value |
|---|---|
| Overall diameter | 31.0 in (787 mm) |
| Sidewall height | 8.0 in (203 mm) |
| Circumference | 97.4 in (2474 mm) |
| Revolutions per mile | 651 |
Typical Fitment
31x10.5R15 is most often found on off-road trucks and SUVs. Always confirm against the door-jamb placard or owner manual before fitting.
Plus-Sizing Alternatives
These sizes keep the overall diameter close to 31x10.5R15, so speedometer and gearing stay near stock:
| Size | Diameter | Diameter change |
|---|---|---|
| 276.7/75R15 | 31.34 in | +1.1% |
| 276.7/70R16 | 31.25 in | +0.8% |
| 286.7/60R17 | 30.54 in | -1.5% |
Speedometer Note
If you fit a 276.7/75R15 instead of 31x10.5R15, the diameter changes by +1.1%. 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 31x10.5R15 against any other size and see the exact diameter and speedometer difference.
Frequently Asked Questions
What does 31x10.5R15 mean?
31x10.5R15 means a 267 mm wide tire with a 76% sidewall aspect ratio mounted on a 15-inch rim. The aspect ratio is the sidewall height as a percentage of the width.
Can I plus-size from 31x10.5R15?
Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 31x10.5R15 are 276.7/75R15, 276.7/70R16, 286.7/60R17.
Will 31x10.5R15 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.