26.4" tall, 12.0" wide, 4.2" sidewall
A 305/35R18 tire is 26.4 inches (671 mm) tall and 12.0 inches wide. The sidewall is 35% of the width, 4.2 inches, on a 18-inch wheel, and the tire turns about 764 times per mile.
In flotation terms that is about 26.4x12.0R18. People often call it a 26-inch tire.
The size most often compared with it is 295/35R18, which is 0.3" shorter (−1.0%). At an indicated 60 mph you would be doing 59.4 mph on it.
| Current | New | Difference |
|---|
| Shows | Actual speed |
|---|
Same 18" wheel, within 20 mm of width and 10 points of aspect ratio.
| Size | Diameter | Width | Sidewall | vs 305/35R18 | |
|---|---|---|---|---|---|
| 295/35R18 | 26.1" | 11.6" | 4.1" | −1.0% | |
| 285/35R18 | 25.9" | 11.2" | 3.9" | −2.1% | |
| 285/40R18 | 27.0" | 11.2" | 4.5" | +2.2% | |
| 295/40R18 | 27.3" | 11.6" | 4.6" | +3.4% | |
| 315/30R18 | 25.4" | 12.4" | 3.7" | −3.7% | |
| 305/30R18 | 25.2" | 12.0" | 3.6" | −4.5% | |
| 295/30R18 | 25.0" | 11.6" | 3.5" | −5.4% | |
| 285/30R18 | 24.7" | 11.2" | 3.4" | −6.3% | |
| 285/45R18 | 28.1" | 11.2" | 5.0" | +6.4% | |
| 295/45R18 | 28.5" | 11.6" | 5.2" | +7.8% |
Sizes within 2% of 26.4" on 17" or 19" wheels.
| Size | Diameter | Width | Sidewall | vs 305/35R18 | |
|---|---|---|---|---|---|
| 295/40R17 | 26.3" | 11.6" | 4.6" | −0.4% | |
| 305/40R17 | 26.6" | 12.0" | 4.8" | +0.8% | |
| 305/30R19 | 26.2" | 12.0" | 3.6" | −0.8% | |
| 205/60R17 | 26.7" | 8.1" | 4.8" | +1.1% | |
| 255/45R17 | 26.0" | 10.0" | 4.5" | −1.4% | |
| 285/40R17 | 26.0" | 11.2" | 4.5" | −1.6% |
Actual speed when the speedometer is calibrated for 305/35R18.
| Speedometer shows | on 295/35R18 | on 285/35R18 | on 285/40R18 |
|---|---|---|---|
| 30 mph | 29.7 mph | 29.4 mph | 30.6 mph |
| 45 mph | 44.5 mph | 44.1 mph | 46.0 mph |
| 60 mph | 59.4 mph | 58.7 mph | 61.3 mph |
| 70 mph | 69.3 mph | 68.5 mph | 71.5 mph |
26.4 inches (671 mm). The sidewall is 4.2 inches.
12.0 inches (305 mm) section width, measured sidewall to sidewall.
About 26.4x12.0R18.
295/35R18 is −1.0% in diameter, within the common 3% guideline. It is 0.4" narrower.