285/55R18 tire size in inches
A 285/55R18 tire measures
30.3" tall × 11.2" wide
6.17" sidewall on a 18" wheel. 665 revolutions per mile.
285/55R18 means a tire 285 mm wide, with sidewalls 55% as tall as the tire is wide (157 mm), radial construction (R), for a 18 inch wheel.
285/55R18 specs
| Overall diameter (height) | 30.34 inches (771 mm) |
|---|---|
| Section width | 11.22 inches (285 mm) |
| Sidewall height | 6.17 inches (157 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 95.3 inches (2,421 mm) |
| Revolutions per mile | 665 |
| Revolutions per kilometer | 413 |
| Approximate rim width | 8.0" to 9.5" |
| In inches (flotation style) | 30.3x11.2R18 |
| 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 285/55R18 on a 18" wheel
These 18" sizes are within 3% of 285/55R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 225/70R18 | 30.40" | 8.86" | +0.2% | 60.1 mph | Compare |
| 315/50R18 | 30.40" | 12.40" | +0.2% | 60.1 mph | Compare |
| 265/60R18 | 30.52" | 10.43" | +0.6% | 60.4 mph | Compare |
| 245/65R18 | 30.54" | 9.65" | +0.6% | 60.4 mph | Compare |
| 205/75R18 | 30.11" | 8.07" | −0.8% | 59.5 mph | Compare |
| 255/60R18 | 30.05" | 10.04" | −1.0% | 59.4 mph | Compare |
| 235/65R18 | 30.03" | 9.25" | −1.0% | 59.4 mph | Compare |
| 305/50R18 | 30.01" | 12.01" | −1.1% | 59.3 mph | Compare |
| 215/75R18 | 30.70" | 8.46" | +1.2% | 60.7 mph | Compare |
| 275/55R18 | 29.91" | 10.83" | −1.4% | 59.1 mph | Compare |
| 295/55R18 | 30.78" | 11.61" | +1.4% | 60.9 mph | Compare |
| 325/50R18 | 30.80" | 12.80" | +1.5% | 60.9 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 265/40R22 | 22" | 30.35" | 0.0% | Compare |
| 235/45R22 | 22" | 30.33" | −0.1% | Compare |
| 355/30R22 | 22" | 30.39" | +0.1% | Compare |
| 215/85R16 | 16" | 30.39" | +0.2% | Compare |
| 265/45R21 | 21" | 30.39" | +0.2% | Compare |
| 295/40R21 | 21" | 30.29" | −0.2% | Compare |
| 225/75R17 | 17" | 30.29" | −0.2% | Compare |
| 245/85R14 | 14" | 30.40" | +0.2% | Compare |
| 325/25R24 | 24" | 30.40" | +0.2% | Compare |
| 305/35R22 | 22" | 30.41" | +0.2% | Compare |
| 265/30R24 | 24" | 30.26" | −0.3% | Compare |
| 235/50R21 | 21" | 30.25" | −0.3% | Compare |
One size up or down
- 275/55R18narrower: 29.9" × 10.8"
- 295/55R18wider: 30.8" × 11.6"
- 285/50R18lower profile: 29.2" × 11.2"
- 285/60R18taller sidewall: 31.5" × 11.2"
Compare 285/55R18 with another size
Questions
- How tall is a 285/55R18 tire?
- A 285/55R18 tire is 30.3 inches tall (771 mm), calculated from the size. It is 11.2 inches wide with 6.2 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 285/55R18 mean?
- 285/55R18 means a tire 285 mm wide, with sidewalls 55% as tall as the tire is wide (157 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 285/55R18 tire make?
- About 665 revolutions per mile, based on a circumference of 95.3 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 285/55R18 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 225/70R18 instead of 285/55R18?
- 225/70R18 is +0.06 inches (+0.2%) in overall diameter, so at an indicated 60 mph you would be doing 60.1 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.