305/65R20 tire size in inches
A 305/65R20 tire measures
35.6" tall × 12.0" wide
7.81" sidewall on a 20" wheel. 566 revolutions per mile.
305/65R20 means a tire 305 mm wide, with sidewalls 65% as tall as the tire is wide (198 mm), radial construction (R), for a 20 inch wheel.
305/65R20 specs
| Overall diameter (height) | 35.61 inches (905 mm) |
|---|---|
| Section width | 12.01 inches (305 mm) |
| Sidewall height | 7.81 inches (198 mm) |
| Wheel (rim) diameter | 20 inches |
| Circumference | 111.9 inches (2,842 mm) |
| Revolutions per mile | 566 |
| Revolutions per kilometer | 352 |
| Approximate rim width | 8.0" to 9.5" |
| In inches (flotation style) | 35.6x12.0R20 |
| Aspect ratio | 65% |
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 305/65R20 on a 20" wheel
These 20" sizes are within 3% of 305/65R20's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 335/60R20 | 35.83" | 13.19" | +0.6% | 60.4 mph | Compare |
| 355/55R20 | 35.37" | 13.98" | −0.7% | 59.6 mph | Compare |
| 325/60R20 | 35.35" | 12.80" | −0.7% | 59.6 mph | Compare |
| 295/65R20 | 35.10" | 11.61" | −1.4% | 59.1 mph | Compare |
| 35x12.50R20 | 35.00" | 12.50" | −1.7% | 59.0 mph | Compare |
| 345/55R20 | 34.94" | 13.58" | −1.9% | 58.9 mph | Compare |
| 315/60R20 | 34.88" | 12.40" | −2.0% | 58.8 mph | Compare |
| 285/65R20 | 34.59" | 11.22" | −2.9% | 58.3 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 315/75R17 | 17" | 35.60" | 0.0% | Compare |
| 325/65R19 | 19" | 35.63" | +0.1% | Compare |
| 345/50R22 | 22" | 35.58" | −0.1% | Compare |
| 315/55R22 | 22" | 35.64" | +0.1% | Compare |
| 335/55R21 | 21" | 35.51" | −0.3% | Compare |
| 295/85R16 | 16" | 35.74" | +0.4% | Compare |
| 355/60R19 | 19" | 35.77" | +0.5% | Compare |
| 295/75R18 | 18" | 35.42" | −0.5% | Compare |
| 315/70R18 | 18" | 35.36" | −0.7% | Compare |
| 325/70R18 | 18" | 35.91" | +0.9% | Compare |
| 345/60R19 | 19" | 35.30" | −0.9% | Compare |
| 345/55R21 | 21" | 35.94" | +0.9% | Compare |
One size up or down
Compare 305/65R20 with another size
Questions
- How tall is a 305/65R20 tire?
- A 305/65R20 tire is 35.6 inches tall (905 mm), calculated from the size. It is 12.0 inches wide with 7.8 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 305/65R20 mean?
- 305/65R20 means a tire 305 mm wide, with sidewalls 65% as tall as the tire is wide (198 mm), radial construction (R), for a 20 inch wheel.
- How many revolutions per mile does a 305/65R20 tire make?
- About 566 revolutions per mile, based on a circumference of 111.9 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 305/65R20 tire?
- Roughly 8.0" to 9.5". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 335/60R20 instead of 305/65R20?
- 335/60R20 is +0.22 inches (+0.6%) in overall diameter, so at an indicated 60 mph you would be doing 60.4 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.