245/55R18 tire size in inches
A 245/55R18 tire measures
28.6" tall × 9.6" wide
5.31" sidewall on a 18" wheel. 705 revolutions per mile.
245/55R18 means a tire 245 mm wide, with sidewalls 55% as tall as the tire is wide (135 mm), radial construction (R), for a 18 inch wheel.
245/55R18 specs
| Overall diameter (height) | 28.61 inches (727 mm) |
|---|---|
| Section width | 9.65 inches (245 mm) |
| Sidewall height | 5.31 inches (135 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 89.9 inches (2,283 mm) |
| Revolutions per mile | 705 |
| Revolutions per kilometer | 438 |
| Approximate rim width | 7.0" to 8.5" |
| In inches (flotation style) | 28.6x9.6R18 |
| 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 245/55R18 on a 18" wheel
These 18" sizes are within 3% of 245/55R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 225/60R18 | 28.63" | 8.86" | +0.1% | 60.0 mph | Compare |
| 335/40R18 | 28.55" | 13.19" | −0.2% | 59.9 mph | Compare |
| 205/65R18 | 28.49" | 8.07" | −0.4% | 59.8 mph | Compare |
| 195/70R18 | 28.75" | 7.68" | +0.5% | 60.3 mph | Compare |
| 295/45R18 | 28.45" | 11.61" | −0.6% | 59.7 mph | Compare |
| 265/50R18 | 28.43" | 10.43" | −0.6% | 59.6 mph | Compare |
| 305/45R18 | 28.81" | 12.01" | +0.7% | 60.4 mph | Compare |
| 275/50R18 | 28.83" | 10.83" | +0.8% | 60.5 mph | Compare |
| 325/40R18 | 28.24" | 12.80" | −1.3% | 59.2 mph | Compare |
| 215/65R18 | 29.00" | 8.46" | +1.4% | 60.8 mph | Compare |
| 235/55R18 | 28.18" | 9.25" | −1.5% | 59.1 mph | Compare |
| 255/55R18 | 29.04" | 10.04" | +1.5% | 60.9 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 265/70R14 | 14" | 28.61" | 0.0% | Compare |
| 305/40R19 | 19" | 28.61" | 0.0% | Compare |
| 295/50R17 | 17" | 28.61" | 0.0% | Compare |
| 335/25R22 | 22" | 28.59" | −0.1% | Compare |
| 275/35R21 | 21" | 28.58" | −0.1% | Compare |
| 245/60R17 | 17" | 28.57" | −0.1% | Compare |
| 245/50R19 | 19" | 28.65" | +0.1% | Compare |
| 265/65R15 | 15" | 28.56" | −0.2% | Compare |
| 275/40R20 | 20" | 28.66" | +0.2% | Compare |
| 215/80R15 | 15" | 28.54" | −0.2% | Compare |
| 325/30R21 | 21" | 28.68" | +0.2% | Compare |
| 245/65R16 | 16" | 28.54" | −0.2% | Compare |
One size up or down
- 235/55R18narrower: 28.2" × 9.3"
- 255/55R18wider: 29.0" × 10.0"
- 245/50R18lower profile: 27.6" × 9.6"
- 245/60R18taller sidewall: 29.6" × 9.6"
Compare 245/55R18 with another size
Questions
- How tall is a 245/55R18 tire?
- A 245/55R18 tire is 28.6 inches tall (727 mm), calculated from the size. It is 9.6 inches wide with 5.3 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 245/55R18 mean?
- 245/55R18 means a tire 245 mm wide, with sidewalls 55% as tall as the tire is wide (135 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 245/55R18 tire make?
- About 705 revolutions per mile, based on a circumference of 89.9 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 245/55R18 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 225/60R18 instead of 245/55R18?
- 225/60R18 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.