315/45R20 tire size in inches
A 315/45R20 tire measures
31.2" tall × 12.4" wide
5.58" sidewall on a 20" wheel. 647 revolutions per mile.
315/45R20 means a tire 315 mm wide, with sidewalls 45% as tall as the tire is wide (142 mm), radial construction (R), for a 20 inch wheel.
315/45R20 specs
| Overall diameter (height) | 31.16 inches (791 mm) |
|---|---|
| Section width | 12.40 inches (315 mm) |
| Sidewall height | 5.58 inches (142 mm) |
| Wheel (rim) diameter | 20 inches |
| Circumference | 97.9 inches (2,487 mm) |
| Revolutions per mile | 647 |
| Revolutions per kilometer | 402 |
| Approximate rim width | 10.5" to 12.0" |
| In inches (flotation style) | 31.2x12.4R20 |
| Aspect ratio | 45% |
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 315/45R20 on a 20" wheel
These 20" sizes are within 3% of 315/45R20's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 355/40R20 | 31.18" | 13.98" | +0.1% | 60.0 mph | Compare |
| 235/60R20 | 31.10" | 9.25" | −0.2% | 59.9 mph | Compare |
| 285/50R20 | 31.22" | 11.22" | +0.2% | 60.1 mph | Compare |
| 255/55R20 | 31.04" | 10.04" | −0.4% | 59.8 mph | Compare |
| 215/65R20 | 31.00" | 8.46" | −0.5% | 59.7 mph | Compare |
| 345/40R20 | 30.87" | 13.58" | −0.9% | 59.4 mph | Compare |
| 265/55R20 | 31.48" | 10.43" | +1.0% | 60.6 mph | Compare |
| 275/50R20 | 30.83" | 10.83" | −1.1% | 59.4 mph | Compare |
| 305/45R20 | 30.81" | 12.01" | −1.1% | 59.3 mph | Compare |
| 225/65R20 | 31.52" | 8.86" | +1.1% | 60.7 mph | Compare |
| 325/45R20 | 31.52" | 12.80" | +1.1% | 60.7 mph | Compare |
| 245/60R20 | 31.57" | 9.65" | +1.3% | 60.8 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 275/70R16 | 16" | 31.16" | 0.0% | Compare |
| 235/55R21 | 21" | 31.18" | +0.1% | Compare |
| 335/50R18 | 18" | 31.19" | +0.1% | Compare |
| 305/30R24 | 24" | 31.20" | +0.1% | Compare |
| 305/55R18 | 18" | 31.21" | +0.2% | Compare |
| 285/45R21 | 21" | 31.10" | −0.2% | Compare |
| 295/65R16 | 16" | 31.10" | −0.2% | Compare |
| 345/45R19 | 19" | 31.22" | +0.2% | Compare |
| 335/35R22 | 22" | 31.23" | +0.2% | Compare |
| 325/40R21 | 21" | 31.24" | +0.2% | Compare |
| 275/75R15 | 15" | 31.24" | +0.3% | Compare |
| 275/65R17 | 17" | 31.07" | −0.3% | Compare |
One size up or down
- 305/45R20narrower: 30.8" × 12.0"
- 325/45R20wider: 31.5" × 12.8"
- 315/40R20lower profile: 29.9" × 12.4"
- 315/50R20taller sidewall: 32.4" × 12.4"
Compare 315/45R20 with another size
Questions
- How tall is a 315/45R20 tire?
- A 315/45R20 tire is 31.2 inches tall (791 mm), calculated from the size. It is 12.4 inches wide with 5.6 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 315/45R20 mean?
- 315/45R20 means a tire 315 mm wide, with sidewalls 45% as tall as the tire is wide (142 mm), radial construction (R), for a 20 inch wheel.
- How many revolutions per mile does a 315/45R20 tire make?
- About 647 revolutions per mile, based on a circumference of 97.9 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 315/45R20 tire?
- Roughly 10.5" to 12.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 355/40R20 instead of 315/45R20?
- 355/40R20 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.