265/65R18 Tire Size
265/65R18 diameter, sidewall, revolutions per mile, and plus-sizing options.
The 265/65R18 tire size breaks down as: 265 mm section width, 65% aspect ratio, and a 18-inch rim. Below are its real, calculated dimensions.
265/65R18 Calculated Dimensions
| Metric | Value |
|---|---|
| Overall diameter | 31.6 in (802 mm) |
| Sidewall height | 6.8 in (172 mm) |
| Circumference | 99.2 in (2519 mm) |
| Revolutions per mile | 639 |
Typical Fitment
265/65R18 is most often found on SUVs and light trucks. Always confirm against the door-jamb placard or owner manual before fitting.
Plus-Sizing Alternatives
These sizes keep the overall diameter close to 265/65R18, so speedometer and gearing stay near stock:
| Size | Diameter | Diameter change |
|---|---|---|
| 275/65R18 | 32.07 in | +1.6% |
| 275/60R19 | 31.99 in | +1.4% |
| 285/50R20 | 31.22 in | -1.1% |
Speedometer Note
If you fit a 275/65R18 instead of 265/65R18, the diameter changes by +1.6%. 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 265/65R18 against any other size and see the exact diameter and speedometer difference.
Frequently Asked Questions
What does 265/65R18 mean?
265/65R18 means a 265 mm wide tire with a 65% sidewall aspect ratio mounted on a 18-inch rim. The aspect ratio is the sidewall height as a percentage of the width.
Can I plus-size from 265/65R18?
Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 265/65R18 are 275/65R18, 275/60R19, 285/50R20.
Will 265/65R18 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.