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285/50R20 tire size in inches
285/50R20 is 31.22" tall and 11.22" wide, and fits a 20" rim. In flotation (inch) sizing that is roughly 31.2x11.2R20.
285/50R20 dimensions
| Measurement | Inches | Metric |
|---|---|---|
| Overall diameter (height) | 31.22" | 793 mm |
| Section width | 11.22" | 285 mm |
| Sidewall height | 5.61" | 142.5 mm |
| Rim diameter | 20" | 508.0 mm |
| Circumference | 98.1" | 2491 mm |
| Revolutions per mile | 646 | |
| Aspect ratio | 50% (sidewall is 50% of the width) | |
Drawn to scale
Among the 131 sizes for 20" wheels on this site, 285/50R20 is #53 by height (shortest: 225/30R20, tallest: 365/85R20).
What people compare 285/50R20 with
Real comparisons drivers search for, worked out against 285/50R20:
| Compared size | Height | Width | Sidewall | Speedo at true 60 |
|---|---|---|---|---|
| 275/55R20 | +0.69" (+2.21%) | -0.39" | +0.34" | 58.7 mph |
| 275/60R20 | +1.77" (+5.67%) | -0.39" | +0.89" | 56.8 mph |
285/50R20 against the most popular 20" sizes
| Popular size | Height | Width | Sidewall | Speedo at true 60 |
|---|---|---|---|---|
| 275/65R20 | +2.85" (+9.13%) | -0.39" | +1.43" | 55 mph |
| 305/55R20 | +1.99" (+6.37%) | +0.79" | +0.99" | 56.4 mph |
| 295/65R20 | +3.88" (+12.43%) | +0.39" | +1.94" | 53.4 mph |
| 295/60R20 | +2.72" (+8.71%) | +0.39" | +1.36" | 55.2 mph |
| 285/60R20 | +2.24" (+7.17%) | 0.00" | +1.12" | 56 mph |
How the 285/50R20 numbers are worked out
The size code reads as 285 mm section width, 50% aspect ratio, R for radial construction and 20-inch wheel.
- Sidewall = 285 × 50% = 142.5 mm = 5.61"
- Diameter = 20" + 2 × 5.61" = 31.22"
- Circumference = π × 31.22" = 98.1"
- Revs per mile = 63,360" ÷ 98.1" = 646
Sizes that can replace 285/50R20 on a 20" wheel
Within 3% of 31.22". Last column: speedometer reading at a true 60 mph.
| Size | Diameter | Width | Difference | Speedo at true 60 mph |
|---|---|---|---|---|
| 355/40R20 | 31.18" | 13.98" | -0.13% | 60.1 mph |
| 315/45R20 | 31.16" | 12.40" | -0.19% | 60.1 mph |
| 235/60R20 | 31.10" | 9.25" | -0.38% | 60.2 mph |
| 255/55R20 | 31.04" | 10.04" | -0.58% | 60.3 mph |
| 265/55R20 | 31.48" | 10.43" | +0.83% | 59.5 mph |
| 325/45R20 | 31.52" | 12.80" | +0.96% | 59.4 mph |
| 245/60R20 | 31.57" | 9.65" | +1.12% | 59.3 mph |
| 275/50R20 | 30.83" | 10.83" | -1.25% | 60.8 mph |
| 295/50R20 | 31.61" | 11.61" | +1.25% | 59.3 mph |
| 305/45R20 | 30.81" | 12.01" | -1.31% | 60.8 mph |
| 270/55R20 | 31.69" | 10.63" | +1.51% | 59.1 mph |
| 245/55R20 | 30.61" | 9.65" | -1.95% | 61.2 mph |
One size wider or narrower
- Narrower: 275/50R20 — 10.83" wide, 30.83" tall
- Wider: 295/50R20 — 11.61" wide, 31.61" tall
Same height on a different wheel size
- 275/75R15 15" (+0.06%)
- 295/70R15 15" (+0.13%)
- 255/80R15 15" (-0.51%)
- 245/85R15 15" (+0.58%)
- 265/80R15 15" (+1.51%)
- 235/85R15 15" (-1.57%)
- 285/70R15 15" (-1.63%)
- 265/75R15 15" (-1.83%)
- 305/70R15 15" (+1.89%)
- 285/75R15 15" (+1.95%)
Questions about 285/50R20
How tall is a 285/50R20 tire in inches?
A 285/50R20 tire is 31.22 inches (793 mm) tall: the 20-inch rim plus two sidewalls of 5.61 inches each.
Is 285/50R20 a 31 inch tire?
Yes. At 31.22 inches tall it is commonly called a 31-inch tire.
How many revolutions per mile does a 285/50R20 make?
About 646 revolutions per mile, based on a calculated circumference of 98.1 inches.
What size can replace 285/50R20?
355/40R20 is the closest match on a 20" rim (-0.13% height). Check load index, speed rating and clearance first.
Compare 285/50R20 against any other size with the tire size calculator.