30.2" tall, 10.8" wide, 7.6" sidewall
A 275/70R15 tire is 30.2 inches (766 mm) tall and 10.8 inches wide. The sidewall is 70% of the width, 7.6 inches, on a 15-inch wheel, and the tire turns about 669 times per mile.
In flotation terms that is about 30.2x10.8R15, closest to the common 30x9.50R15 (30.0"). People often call it a 30-inch tire.
The size most often compared with it is 295/65R15, 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 275/70R15 | |
|---|---|---|---|---|---|
| 295/65R15 | 30.1" | 11.6" | 7.5" | −0.2% | |
| 255/75R15 | 30.1" | 10.0" | 7.5" | −0.3% | |
| 265/75R15 | 30.6" | 10.4" | 7.8" | +1.6% | |
| 265/70R15 | 29.6" | 10.4" | 7.3" | −1.8% | |
| 285/70R15 | 30.7" | 11.2" | 7.9" | +1.8% | |
| 31x10.50R15 | 31.0" | 10.5" | 8.0" | +2.8% | |
| 275/75R15 | 31.2" | 10.8" | 8.1" | +3.6% | |
| 255/70R15 | 29.1" | 10.0" | 7.0" | −3.7% | |
| 295/70R15 | 31.3" | 11.6" | 8.1" | +3.7% | |
| 295/60R15 | 28.9" | 11.6" | 7.0" | −4.0% |
Sizes within 2% of 30.2" on 17" or 16" or 14" wheels.
| Size | Diameter | Width | Sidewall | vs 275/70R15 | |
|---|---|---|---|---|---|
| 305/55R17 | 30.2" | 12.0" | 6.6" | +0.2% | |
| 275/65R16 | 30.1" | 10.8" | 7.0" | −0.3% | |
| 255/80R14 | 30.1" | 10.0" | 8.0" | −0.3% | |
| 255/70R16 | 30.1" | 10.0" | 7.0" | −0.3% | |
| 255/65R17 | 30.1" | 10.0" | 6.5" | −0.4% | |
| 225/75R17 | 30.3" | 8.9" | 6.6" | +0.4% |
Actual speed when the speedometer is calibrated for 275/70R15.
| Speedometer shows | on 295/65R15 | on 255/75R15 | on 265/75R15 |
|---|---|---|---|
| 30 mph | 29.9 mph | 29.9 mph | 30.5 mph |
| 45 mph | 44.9 mph | 44.9 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 |
30.2 inches (766 mm). The sidewall is 7.6 inches.
10.8 inches (275 mm) section width, measured sidewall to sidewall.
About 30.2x10.8R15; the closest common flotation size is 30x9.50R15 at 30.0".
295/65R15 is −0.2% in diameter, within the common 3% guideline. It is 0.8" wider.