27.6" tall, 10.8" wide, 3.8" sidewall
A 275/35R20 tire is 27.6 inches (701 mm) tall and 10.8 inches wide. The sidewall is 35% of the width, 3.8 inches, on a 20-inch wheel, and the tire turns about 731 times per mile.
In flotation terms that is about 27.6x10.8R20. People often call it a 28-inch tire.
The size most often compared with it is 305/30R20, which is 0.4" shorter (−1.4%). At an indicated 60 mph you would be doing 59.2 mph on it.
| Current | New | Difference |
|---|
| Shows | Actual speed |
|---|
Same 20" wheel, within 20 mm of width and 10 points of aspect ratio.
| Size | Diameter | Width | Sidewall | vs 275/35R20 | |
|---|---|---|---|---|---|
| 285/35R20 | 27.9" | 11.2" | 3.9" | +1.0% | compare |
| 265/35R20 | 27.3" | 10.4" | 3.7" | −1.0% | |
| 255/35R20 | 27.0" | 10.0" | 3.5" | −2.0% | compare |
| 295/35R20 | 28.1" | 11.6" | 4.1" | +2.0% | |
| 295/30R20 | 27.0" | 11.6" | 3.5" | −2.2% | |
| 295/40R20 | 29.3" | 11.6" | 4.6" | +6.2% | |
| 295/45R20 | 30.5" | 11.6" | 5.2" | +10.4% |
Sizes within 2% of 27.6" on 18" wheels.
| Size | Diameter | Width | Sidewall | vs 275/35R20 | |
|---|---|---|---|---|---|
| 275/45R18 | 27.7" | 10.8" | 4.9" | +0.6% | |
| 295/40R18 | 27.3" | 11.6" | 4.6" | −1.0% | |
| 255/50R18 | 28.0" | 10.0" | 5.0" | +1.7% | |
| 285/45R18 | 28.1" | 11.2" | 5.0" | +1.9% | |
| 255/45R18 | 27.0" | 10.0" | 4.5" | −2.0% |
Actual speed when the speedometer is calibrated for 275/35R20.
| Speedometer shows | on 305/30R20 | on 255/35R20 | on 285/35R20 |
|---|---|---|---|
| 30 mph | 29.6 mph | 29.4 mph | 30.3 mph |
| 45 mph | 44.4 mph | 44.1 mph | 45.4 mph |
| 60 mph | 59.2 mph | 58.8 mph | 60.6 mph |
| 70 mph | 69.1 mph | 68.6 mph | 70.7 mph |
27.6 inches (701 mm). The sidewall is 3.8 inches.
10.8 inches (275 mm) section width, measured sidewall to sidewall.
About 27.6x10.8R20.
305/30R20 is −1.4% in diameter, within the common 3% guideline. It is 1.2" wider.