28.5" tall, 8.5" wide, 6.8" sidewall
A 215/80R15 tire is 28.5 inches (725 mm) tall and 8.5 inches wide. The sidewall is 80% of the width, 6.8 inches, on a 15-inch wheel, and the tire turns about 707 times per mile.
In flotation terms that is about 28.5x8.5R15. People often call it a 29-inch tire.
The size most often compared with it is 235/75R15, which is 0.3" taller (+1.2%). At an indicated 60 mph you would be doing 60.7 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 215/80R15 | |
|---|---|---|---|---|---|
| 235/75R15 | 28.9" | 9.3" | 6.9" | +1.2% | |
| 235/70R15 | 28.0" | 9.3" | 6.5" | −2.1% | |
| 215/75R15 | 27.7" | 8.5" | 6.3" | −3.0% | |
| 225/70R15 | 27.4" | 8.9" | 6.2" | −4.0% | |
| 195/80R15 | 27.3" | 7.7" | 6.1" | −4.4% | |
| 215/70R15 | 26.9" | 8.5" | 5.9" | −5.9% | |
| 235/85R15 | 30.7" | 9.3" | 7.9" | +7.7% | |
| 205/70R15 | 26.3" | 8.1" | 5.6" | −7.9% |
Sizes within 2% of 28.5" on 16" or 17" wheels.
| Size | Diameter | Width | Sidewall | vs 215/80R15 | |
|---|---|---|---|---|---|
| 245/65R16 | 28.5" | 9.6" | 6.3" | −0.0% | |
| 325/45R17 | 28.5" | 12.8" | 5.8" | −0.1% | |
| 245/60R17 | 28.6" | 9.6" | 5.8" | +0.1% | |
| 275/55R17 | 28.9" | 10.8" | 6.0" | +1.3% | |
| 205/80R16 | 28.9" | 8.1" | 6.5" | +1.3% | |
| 275/60R16 | 29.0" | 10.8" | 6.5" | +1.6% |
Actual speed when the speedometer is calibrated for 215/80R15.
| Speedometer shows | on 235/75R15 | on 235/70R15 | on 215/75R15 |
|---|---|---|---|
| 30 mph | 30.4 mph | 29.4 mph | 29.1 mph |
| 45 mph | 45.5 mph | 44.1 mph | 43.7 mph |
| 60 mph | 60.7 mph | 58.8 mph | 58.2 mph |
| 70 mph | 70.8 mph | 68.6 mph | 67.9 mph |
28.5 inches (725 mm). The sidewall is 6.8 inches.
8.5 inches (215 mm) section width, measured sidewall to sidewall.
About 28.5x8.5R15.
235/75R15 is +1.2% in diameter, within the common 3% guideline. It is 0.8" wider.