255/65R18 tire size in inches
A 255/65R18 tire measures
31.1" tall × 10.0" wide
6.53" sidewall on a 18" wheel. 650 revolutions per mile.
255/65R18 means a tire 255 mm wide, with sidewalls 65% as tall as the tire is wide (166 mm), radial construction (R), for a 18 inch wheel.
255/65R18 specs
| Overall diameter (height) | 31.05 inches (789 mm) |
|---|---|
| Section width | 10.04 inches (255 mm) |
| Sidewall height | 6.53 inches (166 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 97.6 inches (2,478 mm) |
| Revolutions per mile | 650 |
| Revolutions per kilometer | 404 |
| Approximate rim width | 7.0" to 8.5" |
| In inches (flotation style) | 31.1x10.0R18 |
| 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 255/65R18 on a 18" wheel
These 18" sizes are within 3% of 255/65R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 275/60R18 | 30.99" | 10.83" | −0.2% | 59.9 mph | Compare |
| 235/70R18 | 30.95" | 9.25" | −0.3% | 59.8 mph | Compare |
| 335/50R18 | 31.19" | 13.19" | +0.4% | 60.3 mph | Compare |
| 305/55R18 | 31.21" | 12.01" | +0.5% | 60.3 mph | Compare |
| 225/75R18 | 31.29" | 8.86" | +0.8% | 60.5 mph | Compare |
| 325/50R18 | 30.80" | 12.80" | −0.8% | 59.5 mph | Compare |
| 295/55R18 | 30.78" | 11.61" | −0.9% | 59.5 mph | Compare |
| 215/75R18 | 30.70" | 8.46" | −1.1% | 59.3 mph | Compare |
| 285/60R18 | 31.46" | 11.22" | +1.3% | 60.8 mph | Compare |
| 245/70R18 | 31.50" | 9.65" | +1.5% | 60.9 mph | Compare |
| 265/65R18 | 31.56" | 10.43" | +1.6% | 61.0 mph | Compare |
| 245/65R18 | 30.54" | 9.65" | −1.6% | 59.0 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 255/70R17 | 17" | 31.06" | 0.0% | Compare |
| 255/60R19 | 19" | 31.05" | 0.0% | Compare |
| 225/85R16 | 16" | 31.06" | 0.0% | Compare |
| 255/75R16 | 16" | 31.06" | 0.0% | Compare |
| 255/55R20 | 20" | 31.04" | 0.0% | Compare |
| 255/80R15 | 15" | 31.06" | 0.0% | Compare |
| 255/50R21 | 21" | 31.04" | 0.0% | Compare |
| 255/85R14 | 14" | 31.07" | +0.1% | Compare |
| 255/45R22 | 22" | 31.04" | −0.1% | Compare |
| 275/65R17 | 17" | 31.07" | +0.1% | Compare |
| 235/65R19 | 19" | 31.03" | −0.1% | Compare |
| 255/35R24 | 24" | 31.03" | −0.1% | Compare |
One size up or down
- 245/65R18narrower: 30.5" × 9.6"
- 265/65R18wider: 31.6" × 10.4"
- 255/60R18lower profile: 30.0" × 10.0"
- 255/70R18taller sidewall: 32.1" × 10.0"
Compare 255/65R18 with another size
Questions
- How tall is a 255/65R18 tire?
- A 255/65R18 tire is 31.1 inches tall (789 mm), calculated from the size. It is 10.0 inches wide with 6.5 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 255/65R18 mean?
- 255/65R18 means a tire 255 mm wide, with sidewalls 65% as tall as the tire is wide (166 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 255/65R18 tire make?
- About 650 revolutions per mile, based on a circumference of 97.6 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 255/65R18 tire?
- Roughly 7.0" to 8.5". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 275/60R18 instead of 255/65R18?
- 275/60R18 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.