285/40R20 tire size in inches
A 285/40R20 tire measures
29.0" tall × 11.2" wide
4.49" sidewall on a 20" wheel. 696 revolutions per mile.
285/40R20 means a tire 285 mm wide, with sidewalls 40% as tall as the tire is wide (114 mm), radial construction (R), for a 20 inch wheel.
285/40R20 specs
| Overall diameter (height) | 28.98 inches (736 mm) |
|---|---|
| Section width | 11.22 inches (285 mm) |
| Sidewall height | 4.49 inches (114 mm) |
| Wheel (rim) diameter | 20 inches |
| Circumference | 91.0 inches (2,312 mm) |
| Revolutions per mile | 696 |
| Revolutions per kilometer | 432 |
| Approximate rim width | 9.5" to 11.0" |
| In inches (flotation style) | 29.0x11.2R20 |
| Aspect ratio | 40% |
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 285/40R20 on a 20" wheel
These 20" sizes are within 3% of 285/40R20's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 325/35R20 | 28.96" | 12.80" | −0.1% | 60.0 mph | Compare |
| 255/45R20 | 29.04" | 10.04" | +0.2% | 60.1 mph | Compare |
| 225/50R20 | 28.86" | 8.86" | −0.4% | 59.8 mph | Compare |
| 335/35R20 | 29.23" | 13.19" | +0.9% | 60.5 mph | Compare |
| 235/50R20 | 29.25" | 9.25" | +1.0% | 60.6 mph | Compare |
| 245/45R20 | 28.68" | 9.65" | −1.0% | 59.4 mph | Compare |
| 315/35R20 | 28.68" | 12.40" | −1.0% | 59.4 mph | Compare |
| 275/40R20 | 28.66" | 10.83" | −1.1% | 59.3 mph | Compare |
| 295/40R20 | 29.29" | 11.61" | +1.1% | 60.7 mph | Compare |
| 215/55R20 | 29.31" | 8.46" | +1.2% | 60.7 mph | Compare |
| 265/45R20 | 29.39" | 10.43" | +1.4% | 60.9 mph | Compare |
| 215/50R20 | 28.46" | 8.46" | −1.8% | 58.9 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 225/45R21 | 21" | 28.97" | 0.0% | Compare |
| 295/30R22 | 22" | 28.97" | 0.0% | Compare |
| 355/25R22 | 22" | 28.99" | 0.0% | Compare |
| 275/60R16 | 16" | 28.99" | +0.1% | Compare |
| 235/70R16 | 16" | 28.95" | −0.1% | Compare |
| 215/65R18 | 18" | 29.00" | +0.1% | Compare |
| 305/50R17 | 17" | 29.01" | +0.1% | Compare |
| 255/25R24 | 24" | 29.02" | +0.1% | Compare |
| 235/65R17 | 17" | 29.03" | +0.2% | Compare |
| 255/35R22 | 22" | 29.03" | +0.2% | Compare |
| 315/40R19 | 19" | 28.92" | −0.2% | Compare |
| 255/40R21 | 21" | 29.03" | +0.2% | Compare |
One size up or down
- 275/40R20narrower: 28.7" × 10.8"
- 295/40R20wider: 29.3" × 11.6"
- 285/35R20lower profile: 27.9" × 11.2"
- 285/45R20taller sidewall: 30.1" × 11.2"
Compare 285/40R20 with another size
Questions
- How tall is a 285/40R20 tire?
- A 285/40R20 tire is 29.0 inches tall (736 mm), calculated from the size. It is 11.2 inches wide with 4.5 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 285/40R20 mean?
- 285/40R20 means a tire 285 mm wide, with sidewalls 40% as tall as the tire is wide (114 mm), radial construction (R), for a 20 inch wheel.
- How many revolutions per mile does a 285/40R20 tire make?
- About 696 revolutions per mile, based on a circumference of 91.0 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 285/40R20 tire?
- Roughly 9.5" to 11.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 325/35R20 instead of 285/40R20?
- 325/35R20 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.