245/45R18 tire size in inches
A 245/45R18 tire measures
26.7" tall × 9.6" wide
4.34" sidewall on a 18" wheel. 756 revolutions per mile.
245/45R18 means a tire 245 mm wide, with sidewalls 45% as tall as the tire is wide (110 mm), radial construction (R), for a 18 inch wheel.
245/45R18 specs
| Overall diameter (height) | 26.68 inches (678 mm) |
|---|---|
| Section width | 9.65 inches (245 mm) |
| Sidewall height | 4.34 inches (110 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 83.8 inches (2,129 mm) |
| Revolutions per mile | 756 |
| Revolutions per kilometer | 470 |
| Approximate rim width | 8.0" to 9.5" |
| In inches (flotation style) | 26.7x9.6R18 |
| Aspect ratio | 45% |
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 245/45R18 on a 18" wheel
These 18" sizes are within 3% of 245/45R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 315/35R18 | 26.68" | 12.40" | 0.0% | 60.0 mph | Compare |
| 275/40R18 | 26.66" | 10.83" | −0.1% | 60.0 mph | Compare |
| 225/50R18 | 26.86" | 8.86" | +0.7% | 60.4 mph | Compare |
| 205/55R18 | 26.88" | 8.07" | +0.7% | 60.4 mph | Compare |
| 215/50R18 | 26.46" | 8.46" | −0.8% | 59.5 mph | Compare |
| 195/55R18 | 26.44" | 7.68" | −0.9% | 59.5 mph | Compare |
| 305/35R18 | 26.41" | 12.01" | −1.0% | 59.4 mph | Compare |
| 325/35R18 | 26.96" | 12.80" | +1.0% | 60.6 mph | Compare |
| 285/40R18 | 26.98" | 11.22" | +1.1% | 60.7 mph | Compare |
| 265/40R18 | 26.35" | 10.43" | −1.3% | 59.2 mph | Compare |
| 255/45R18 | 27.04" | 10.04" | +1.3% | 60.8 mph | Compare |
| 235/45R18 | 26.33" | 9.25" | −1.3% | 59.2 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 205/60R17 | 17" | 26.69" | 0.0% | Compare |
| 325/30R19 | 19" | 26.68" | 0.0% | Compare |
| 215/75R14 | 14" | 26.70" | +0.1% | Compare |
| 185/80R15 | 15" | 26.65" | −0.1% | Compare |
| 175/85R15 | 15" | 26.71" | +0.1% | Compare |
| 245/50R17 | 17" | 26.65" | −0.1% | Compare |
| 245/40R19 | 19" | 26.72" | +0.1% | Compare |
| 205/85R13 | 13" | 26.72" | +0.1% | Compare |
| 285/30R20 | 20" | 26.73" | +0.2% | Compare |
| 225/60R16 | 16" | 26.63" | −0.2% | Compare |
| 235/25R22 | 22" | 26.63" | −0.2% | Compare |
| 215/45R19 | 19" | 26.62" | −0.2% | Compare |
One size up or down
- 235/45R18narrower: 26.3" × 9.3"
- 255/45R18wider: 27.0" × 10.0"
- 245/40R18lower profile: 25.7" × 9.6"
- 245/50R18taller sidewall: 27.6" × 9.6"
Compare 245/45R18 with another size
Questions
- How tall is a 245/45R18 tire?
- A 245/45R18 tire is 26.7 inches tall (678 mm), calculated from the size. It is 9.6 inches wide with 4.3 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 245/45R18 mean?
- 245/45R18 means a tire 245 mm wide, with sidewalls 45% as tall as the tire is wide (110 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 245/45R18 tire make?
- About 756 revolutions per mile, based on a circumference of 83.8 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 245/45R18 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 315/35R18 instead of 245/45R18?
- 315/35R18 is 0.00 inches (0.0%) 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.