28.1" tall, 10.0" wide, 6.5" sidewall
A 255/65R15 tire is 28.1 inches (713 mm) tall and 10.0 inches wide. The sidewall is 65% of the width, 6.5 inches, on a 15-inch wheel, and the tire turns about 719 times per mile.
In flotation terms that is about 28.1x10.0R15. People often call it a 28-inch tire.
The size most often compared with it is 275/60R15, which is 0.1" shorter (−0.2%). At an indicated 60 mph you would be doing 59.9 mph on it.
| Current | New | Difference |
|---|
| Shows | Actual speed |
|---|
Same 15" wheel, within 20 mm of width and 10 points of aspect ratio.
| Size | Diameter | Width | Sidewall | vs 255/65R15 | |
|---|---|---|---|---|---|
| 275/60R15 | 28.0" | 10.8" | 6.5" | −0.2% | |
| 235/70R15 | 28.0" | 9.3" | 6.5" | −0.4% | |
| 245/70R15 | 28.5" | 9.6" | 6.8" | +1.6% | |
| 265/65R15 | 28.6" | 10.4" | 6.8" | +1.8% | |
| 235/75R15 | 28.9" | 9.3" | 6.9" | +2.9% | |
| 255/60R15 | 27.0" | 10.0" | 6.0" | −3.6% | |
| 255/70R15 | 29.1" | 10.0" | 7.0" | +3.6% | |
| 235/65R15 | 27.0" | 9.3" | 6.0" | −3.6% | |
| 275/55R15 | 26.9" | 10.8" | 6.0" | −4.1% | |
| 245/75R15 | 29.5" | 9.6" | 7.2" | +5.1% |
Sizes within 2% of 28.1" on 17" or 16" wheels.
| Size | Diameter | Width | Sidewall | vs 255/65R15 | |
|---|---|---|---|---|---|
| 275/50R17 | 27.8" | 10.8" | 5.4" | −0.8% | |
| 245/55R17 | 27.6" | 9.6" | 5.3" | −1.6% | |
| 325/45R17 | 28.5" | 12.8" | 5.8" | +1.7% | |
| 245/65R16 | 28.5" | 9.6" | 6.3" | +1.7% | |
| 245/60R17 | 28.6" | 9.6" | 5.8" | +1.9% | |
| 205/65R17 | 27.5" | 8.1" | 5.2" | −2.0% |
Actual speed when the speedometer is calibrated for 255/65R15.
| Speedometer shows | on 275/60R15 | on 235/70R15 | on 245/70R15 |
|---|---|---|---|
| 30 mph | 29.9 mph | 29.9 mph | 30.5 mph |
| 45 mph | 44.9 mph | 44.8 mph | 45.7 mph |
| 60 mph | 59.9 mph | 59.8 mph | 61.0 mph |
| 70 mph | 69.9 mph | 69.8 mph | 71.1 mph |
28.1 inches (713 mm). The sidewall is 6.5 inches.
10.0 inches (255 mm) section width, measured sidewall to sidewall.
About 28.1x10.0R15.
275/60R15 is −0.2% in diameter, within the common 3% guideline. It is 0.8" wider.