31.4" tall, 12.0" wide, 7.2" sidewall
A 305/60R17 tire is 31.4 inches (798 mm) tall and 12.0 inches wide. The sidewall is 60% of the width, 7.2 inches, on a 17-inch wheel, and the tire turns about 642 times per mile.
In flotation terms that is about 31.4x12.0R17. People often call it a 31-inch tire.
The size most often compared with it is 285/65R17, which is 0.2" taller (+0.6%). At an indicated 60 mph you would be doing 60.3 mph on it.
| Current | New | Difference |
|---|
| Shows | Actual speed |
|---|
Same 17" wheel, within 20 mm of width and 10 points of aspect ratio.
| Size | Diameter | Width | Sidewall | vs 305/60R17 | |
|---|---|---|---|---|---|
| 285/65R17 | 31.6" | 11.2" | 7.3" | +0.6% | |
| 315/60R17 | 31.9" | 12.4" | 7.4" | +1.5% | |
| 295/65R17 | 32.1" | 11.6" | 7.5" | +2.2% | |
| 315/55R17 | 30.6" | 12.4" | 6.8" | −2.4% | |
| 285/60R17 | 30.5" | 11.2" | 6.7" | −3.0% | |
| 305/55R17 | 30.2" | 12.0" | 6.6" | −3.8% | |
| 305/65R17 | 32.6" | 12.0" | 7.8" | +3.8% | |
| 285/70R17 | 32.7" | 11.2" | 7.9" | +4.1% | |
| 33x12.50R17 | 33.0" | 12.5" | 8.0" | +5.1% | |
| 315/65R17 | 33.1" | 12.4" | 8.1" | +5.5% |
Sizes within 2% of 31.4" on 19" or 16" or 18" or 15" wheels.
| Size | Diameter | Width | Sidewall | vs 305/60R17 | |
|---|---|---|---|---|---|
| 225/70R19 | 31.4" | 8.9" | 6.2" | −0.0% | |
| 245/80R16 | 31.4" | 9.6" | 7.7" | +0.1% | |
| 285/60R18 | 31.5" | 11.2" | 6.7" | +0.2% | |
| 245/70R18 | 31.5" | 9.6" | 6.8" | +0.3% | |
| 295/70R15 | 31.3" | 11.6" | 8.1" | −0.5% | |
| 265/65R18 | 31.6" | 10.4" | 6.8" | +0.5% |
Actual speed when the speedometer is calibrated for 305/60R17.
| Speedometer shows | on 285/65R17 | on 315/60R17 | on 295/65R17 |
|---|---|---|---|
| 30 mph | 30.2 mph | 30.5 mph | 30.7 mph |
| 45 mph | 45.3 mph | 45.7 mph | 46.0 mph |
| 60 mph | 60.3 mph | 60.9 mph | 61.3 mph |
| 70 mph | 70.4 mph | 71.1 mph | 71.5 mph |
31.4 inches (798 mm). The sidewall is 7.2 inches.
12.0 inches (305 mm) section width, measured sidewall to sidewall.
About 31.4x12.0R17.
285/65R17 is +0.6% in diameter, within the common 3% guideline. It is 0.8" narrower.