255/50R18 tire size in inches
A 255/50R18 tire measures
28.0" tall × 10.0" wide
5.02" sidewall on a 18" wheel. 719 revolutions per mile.
255/50R18 means a tire 255 mm wide, with sidewalls 50% as tall as the tire is wide (127 mm), radial construction (R), for a 18 inch wheel.
255/50R18 specs
| Overall diameter (height) | 28.04 inches (712 mm) |
|---|---|
| Section width | 10.04 inches (255 mm) |
| Sidewall height | 5.02 inches (127 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 88.1 inches (2,237 mm) |
| Revolutions per mile | 719 |
| Revolutions per kilometer | 447 |
| Approximate rim width | 7.5" to 9.0" |
| In inches (flotation style) | 28.0x10.0R18 |
| Aspect ratio | 50% |
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 255/50R18 on a 18" wheel
These 18" sizes are within 3% of 255/50R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 195/65R18 | 27.98" | 7.68" | −0.2% | 59.9 mph | Compare |
| 285/45R18 | 28.10" | 11.22" | +0.2% | 60.1 mph | Compare |
| 315/40R18 | 27.92" | 12.40" | −0.4% | 59.7 mph | Compare |
| 215/60R18 | 28.16" | 8.46" | +0.4% | 60.3 mph | Compare |
| 235/55R18 | 28.18" | 9.25" | +0.5% | 60.3 mph | Compare |
| 325/40R18 | 28.24" | 12.80" | +0.7% | 60.4 mph | Compare |
| 225/55R18 | 27.74" | 8.86" | −1.1% | 59.4 mph | Compare |
| 275/45R18 | 27.74" | 10.83" | −1.1% | 59.4 mph | Compare |
| 205/60R18 | 27.69" | 8.07" | −1.3% | 59.2 mph | Compare |
| 245/50R18 | 27.65" | 9.65" | −1.4% | 59.2 mph | Compare |
| 265/50R18 | 28.43" | 10.43" | +1.4% | 60.8 mph | Compare |
| 295/45R18 | 28.45" | 11.61" | +1.5% | 60.9 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 255/45R19 | 19" | 28.04" | 0.0% | Compare |
| 255/55R17 | 17" | 28.04" | 0.0% | Compare |
| 255/40R20 | 20" | 28.03" | 0.0% | Compare |
| 255/60R16 | 16" | 28.05" | 0.0% | Compare |
| 235/65R16 | 16" | 28.03" | 0.0% | Compare |
| 255/35R21 | 21" | 28.03" | 0.0% | Compare |
| 195/85R15 | 15" | 28.05" | 0.0% | Compare |
| 255/65R15 | 15" | 28.05" | 0.0% | Compare |
| 255/30R22 | 22" | 28.02" | −0.1% | Compare |
| 255/70R14 | 14" | 28.06" | +0.1% | Compare |
| 225/85R13 | 13" | 28.06" | +0.1% | Compare |
| 215/65R17 | 17" | 28.00" | −0.1% | Compare |
One size up or down
- 245/50R18narrower: 27.6" × 9.6"
- 265/50R18wider: 28.4" × 10.4"
- 255/45R18lower profile: 27.0" × 10.0"
- 255/55R18taller sidewall: 29.0" × 10.0"
Compare 255/50R18 with another size
Questions
- How tall is a 255/50R18 tire?
- A 255/50R18 tire is 28.0 inches tall (712 mm), calculated from the size. It is 10.0 inches wide with 5.0 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 255/50R18 mean?
- 255/50R18 means a tire 255 mm wide, with sidewalls 50% as tall as the tire is wide (127 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 255/50R18 tire make?
- About 719 revolutions per mile, based on a circumference of 88.1 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 255/50R18 tire?
- Roughly 7.5" to 9.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 195/65R18 instead of 255/50R18?
- 195/65R18 is −0.06 inches (−0.2%) in overall diameter, so at an indicated 60 mph you would be doing 59.9 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.