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305/60R20 tire size in inches
305/60R20 is 34.41" tall and 12.01" wide, and fits a 20" rim. In flotation (inch) sizing that is roughly 34.4x12.0R20.
305/60R20 dimensions
| Measurement | Inches | Metric |
|---|---|---|
| Overall diameter (height) | 34.41" | 874 mm |
| Section width | 12.01" | 305 mm |
| Sidewall height | 7.20" | 183.0 mm |
| Rim diameter | 20" | 508.0 mm |
| Circumference | 108.1" | 2746 mm |
| Revolutions per mile | 586 | |
| Aspect ratio | 60% (sidewall is 60% of the width) | |
Drawn to scale
Among the 131 sizes for 20" wheels on this site, 305/60R20 is #88 by height (shortest: 225/30R20, tallest: 365/85R20).
305/60R20 against the most popular 20" sizes
| Popular size | Height | Width | Sidewall | Speedo at true 60 |
|---|---|---|---|---|
| 275/60R20 | -1.42" (-4.13%) | -1.18" | -0.70" | 62.6 mph |
| 275/65R20 | -0.34" (-0.99%) | -1.18" | -0.16" | 60.6 mph |
| 275/55R20 | -2.50" (-7.27%) | -1.18" | -1.25" | 64.7 mph |
| 305/55R20 | -1.20" (-3.49%) | 0.00" | -0.60" | 62.2 mph |
| 295/65R20 | +0.69" (+2.01%) | -0.40" | +0.35" | 58.8 mph |
How the 305/60R20 numbers are worked out
The size code reads as 305 mm section width, 60% aspect ratio, R for radial construction and 20-inch wheel.
- Sidewall = 305 × 60% = 183.0 mm = 7.20"
- Diameter = 20" + 2 × 7.20" = 34.41"
- Circumference = π × 34.41" = 108.1"
- Revs per mile = 63,360" ÷ 108.1" = 586
Sizes that can replace 305/60R20 on a 20" wheel
Within 3% of 34.41". Last column: speedometer reading at a true 60 mph.
| Size | Diameter | Width | Difference | Speedo at true 60 mph |
|---|---|---|---|---|
| 280/65R20 | 34.33" | 11.02" | -0.23% | 60.1 mph |
| 285/65R20 | 34.59" | 11.22" | +0.52% | 59.7 mph |
| 265/70R20 | 34.61" | 10.43" | +0.58% | 59.7 mph |
| 275/65R20 | 34.07" | 10.83" | -0.99% | 60.6 mph |
| 325/55R20 | 34.07" | 12.80" | -0.99% | 60.6 mph |
| 255/70R20 | 34.06" | 10.04" | -1.02% | 60.6 mph |
| 290/65R20 | 34.84" | 11.42" | +1.25% | 59.3 mph |
| 355/50R20 | 33.98" | 13.98" | -1.25% | 60.8 mph |
| 295/60R20 | 33.94" | 11.61" | -1.37% | 60.8 mph |
| 315/60R20 | 34.88" | 12.40" | +1.37% | 59.2 mph |
| 345/55R20 | 34.94" | 13.58" | +1.54% | 59.1 mph |
| 270/65R20 | 33.82" | 10.63" | -1.71% | 61 mph |
One size wider or narrower
Same height on a different wheel size
- 325/75R15 15" (-0.64%)
- 275/85R16 16" (0%)
- 295/80R16 16" (+0.49%)
- 315/75R16 16" (+0.55%)
- 305/75R16 16" (-1.16%)
- 285/80R16 16" (-1.34%)
- 325/70R16 16" (-1.45%)
- 285/85R16 16" (+1.92%)
- 265/85R16 16" (-1.95%)
- 295/75R17 17" (+0.03%)
Questions about 305/60R20
How tall is a 305/60R20 tire in inches?
A 305/60R20 tire is 34.41 inches (874 mm) tall: the 20-inch rim plus two sidewalls of 7.20 inches each.
Is 305/60R20 a 34 inch tire?
Yes. At 34.41 inches tall it is commonly called a 34-inch tire.
How many revolutions per mile does a 305/60R20 make?
About 586 revolutions per mile, based on a calculated circumference of 108.1 inches.
What size can replace 305/60R20?
280/65R20 is the closest match on a 20" rim (-0.23% height). Check load index, speed rating and clearance first.
Compare 305/60R20 against any other size with the tire size calculator.