27.0" tall, 10.0" wide, 6.0" sidewall
A 255/60R15 tire is 27.0 inches (687 mm) tall and 10.0 inches wide. The sidewall is 60% of the width, 6.0 inches, on a 15-inch wheel, and the tire turns about 746 times per mile.
In flotation terms that is about 27.0x10.0R15. People often call it a 27-inch tire.
The size most often compared with it is 275/60R15, which is 0.9" taller (+3.5%). At an indicated 60 mph you would be doing 62.1 mph on it, more than the 3% change many shops use as a limit.
| 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 255/60R15 | |
|---|---|---|---|---|---|
| 235/65R15 | 27.0" | 9.3" | 6.0" | −0.1% | |
| 275/55R15 | 26.9" | 10.8" | 6.0" | −0.5% | |
| 245/60R15 | 26.6" | 9.6" | 5.8" | −1.7% | compare |
| 235/70R15 | 28.0" | 9.3" | 6.5" | +3.3% | |
| 235/60R15 | 26.1" | 9.3" | 5.6" | −3.5% | compare |
| 275/60R15 | 28.0" | 10.8" | 6.5" | +3.5% | compare |
| 255/55R15 | 26.0" | 10.0" | 5.5" | −3.7% | |
| 255/65R15 | 28.1" | 10.0" | 6.5" | +3.7% | |
| 275/50R15 | 25.8" | 10.8" | 5.4" | −4.5% | compare |
| 245/55R15 | 25.6" | 9.6" | 5.3" | −5.3% |
Sizes within 2% of 27.0" on 14" or 17" wheels.
| Size | Diameter | Width | Sidewall | vs 255/60R15 | |
|---|---|---|---|---|---|
| 255/65R14 | 27.1" | 10.0" | 6.5" | +0.0% | |
| 285/45R17 | 27.1" | 11.2" | 5.0" | +0.2% | |
| 215/75R14 | 26.7" | 8.5" | 6.3" | −1.3% | |
| 205/60R17 | 26.7" | 8.1" | 4.8" | −1.3% | |
| 265/50R17 | 27.4" | 10.4" | 5.2" | +1.4% | |
| 305/40R17 | 26.6" | 12.0" | 4.8" | −1.6% |
Actual speed when the speedometer is calibrated for 255/60R15.
| Speedometer shows | on 275/60R15 | on 295/50R15 | on 225/70R15 |
|---|---|---|---|
| 30 mph | 31.0 mph | 29.5 mph | 30.4 mph |
| 45 mph | 46.6 mph | 44.3 mph | 45.6 mph |
| 60 mph | 62.1 mph | 59.0 mph | 60.8 mph |
| 70 mph | 72.4 mph | 68.9 mph | 70.9 mph |
27.0 inches (687 mm). The sidewall is 6.0 inches.
10.0 inches (255 mm) section width, measured sidewall to sidewall.
About 27.0x10.0R15.
275/60R15 is +3.5% in diameter, more than the common 3% guideline, so expect a speedometer error and check clearance. It is 0.8" wider.