305/55R20 tire size in inches
A 305/55R20 tire measures
33.2" tall × 12.0" wide
6.60" sidewall on a 20" wheel. 607 revolutions per mile.
305/55R20 means a tire 305 mm wide, with sidewalls 55% as tall as the tire is wide (168 mm), radial construction (R), for a 20 inch wheel.
305/55R20 specs
| Overall diameter (height) | 33.21 inches (844 mm) |
|---|---|
| Section width | 12.01 inches (305 mm) |
| Sidewall height | 6.60 inches (168 mm) |
| Wheel (rim) diameter | 20 inches |
| Circumference | 104.3 inches (2,650 mm) |
| Revolutions per mile | 607 |
| Revolutions per kilometer | 377 |
| Approximate rim width | 9.0" to 10.5" |
| In inches (flotation style) | 33.2x12.0R20 |
| Aspect ratio | 55% |
Calculated from the size. Real tires differ by brand, model and tread depth, typically by a few tenths of an inch.
Sizes that can replace 305/55R20 on a 20" wheel
These 20" sizes are within 3% of 305/55R20's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 335/50R20 | 33.19" | 13.19" | −0.1% | 60.0 mph | Compare |
| 255/65R20 | 33.05" | 10.04" | −0.5% | 59.7 mph | Compare |
| 33x12.50R20 | 33.00" | 12.50" | −0.6% | 59.6 mph | Compare |
| 275/60R20 | 32.99" | 10.83" | −0.7% | 59.6 mph | Compare |
| 285/60R20 | 33.46" | 11.22" | +0.8% | 60.5 mph | Compare |
| 265/65R20 | 33.56" | 10.43" | +1.1% | 60.6 mph | Compare |
| 345/50R20 | 33.58" | 13.58" | +1.1% | 60.7 mph | Compare |
| 325/50R20 | 32.80" | 12.80" | −1.2% | 59.3 mph | Compare |
| 295/55R20 | 32.78" | 11.61" | −1.3% | 59.2 mph | Compare |
| 315/55R20 | 33.64" | 12.40" | +1.3% | 60.8 mph | Compare |
| 355/45R20 | 32.58" | 13.98" | −1.9% | 58.9 mph | Compare |
| 245/65R20 | 32.54" | 9.65" | −2.0% | 58.8 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 285/50R22 | 22" | 33.22" | 0.0% | Compare |
| 345/45R21 | 21" | 33.22" | 0.0% | Compare |
| 335/35R24 | 24" | 33.23" | +0.1% | Compare |
| 355/40R22 | 22" | 33.18" | −0.1% | Compare |
| 275/75R17 | 17" | 33.24" | +0.1% | Compare |
| 315/45R22 | 22" | 33.16" | −0.1% | Compare |
| 295/70R17 | 17" | 33.26" | +0.2% | Compare |
| 275/70R18 | 18" | 33.16" | −0.2% | Compare |
| 295/40R24 | 24" | 33.29" | +0.2% | Compare |
| 315/65R17 | 17" | 33.12" | −0.3% | Compare |
| 295/65R18 | 18" | 33.10" | −0.3% | Compare |
| 275/80R16 | 16" | 33.32" | +0.3% | Compare |
One size up or down
- 295/55R20narrower: 32.8" × 11.6"
- 315/55R20wider: 33.6" × 12.4"
- 305/50R20lower profile: 32.0" × 12.0"
- 305/60R20taller sidewall: 34.4" × 12.0"
Compare 305/55R20 with another size
Questions
- How tall is a 305/55R20 tire?
- A 305/55R20 tire is 33.2 inches tall (844 mm), calculated from the size. It is 12.0 inches wide with 6.6 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 305/55R20 mean?
- 305/55R20 means a tire 305 mm wide, with sidewalls 55% as tall as the tire is wide (168 mm), radial construction (R), for a 20 inch wheel.
- How many revolutions per mile does a 305/55R20 tire make?
- About 607 revolutions per mile, based on a circumference of 104.3 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 305/55R20 tire?
- Roughly 9.0" to 10.5". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 335/50R20 instead of 305/55R20?
- 335/50R20 is −0.02 inches (−0.1%) in overall diameter, so at an indicated 60 mph you would be doing 60.0 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.