LT245/70R17 Tire Size
LT245/70R17 diameter, sidewall, revolutions per mile, and plus-sizing options.
The LT245/70R17 tire size breaks down as: 245 mm section width, 70% aspect ratio, and a 17-inch rim. Below are its real, calculated dimensions.
LT245/70R17 Calculated Dimensions
| Metric | Value |
|---|---|
| Overall diameter | 30.5 in (775 mm) |
| Sidewall height | 6.8 in (172 mm) |
| Circumference | 95.8 in (2434 mm) |
| Revolutions per mile | 661 |
Typical Fitment
LT245/70R17 is most often found on mid-size pickups. Always confirm against the door-jamb placard or owner manual before fitting.
Plus-Sizing Alternatives
These sizes keep the overall diameter close to LT245/70R17, so speedometer and gearing stay near stock:
| Size | Diameter | Diameter change |
|---|---|---|
| 255/65R17 | 30.05 in | -1.5% |
| 255/60R18 | 30.05 in | -1.5% |
| 265/55R19 | 30.48 in | -0.1% |
Speedometer Note
If you fit a 255/65R17 instead of LT245/70R17, the diameter changes by -1.5%. A taller tire makes your speedometer read low — at a true 60 mph it would show roughly 61 mph. A shorter tire has the opposite effect, so the gauge reads high.
Use the tire calculator to compare LT245/70R17 against any other size and see the exact diameter and speedometer difference.
Frequently Asked Questions
What does LT245/70R17 mean?
LT245/70R17 means a 245 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 LT245/70R17?
Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from LT245/70R17 are 255/65R17, 255/60R18, 265/55R19.
Will LT245/70R17 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.