215/45R18 tire size in inches
A 215/45R18 tire measures
25.6" tall × 8.5" wide
3.81" sidewall on a 18" wheel. 787 revolutions per mile.
215/45R18 means a tire 215 mm wide, with sidewalls 45% as tall as the tire is wide (97 mm), radial construction (R), for a 18 inch wheel.
215/45R18 specs
| Overall diameter (height) | 25.62 inches (651 mm) |
|---|---|
| Section width | 8.46 inches (215 mm) |
| Sidewall height | 3.81 inches (97 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 80.5 inches (2,044 mm) |
| Revolutions per mile | 787 |
| Revolutions per kilometer | 489 |
| Approximate rim width | 7.0" to 8.5" |
| In inches (flotation style) | 25.6x8.5R18 |
| 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 215/45R18 on a 18" wheel
These 18" sizes are within 3% of 215/45R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 275/35R18 | 25.58" | 10.83" | −0.2% | 59.9 mph | Compare |
| 195/50R18 | 25.68" | 7.68" | +0.2% | 60.1 mph | Compare |
| 245/40R18 | 25.72" | 9.65" | +0.4% | 60.2 mph | Compare |
| 235/40R18 | 25.40" | 9.25" | −0.8% | 59.5 mph | Compare |
| 285/35R18 | 25.85" | 11.22" | +0.9% | 60.6 mph | Compare |
| 265/35R18 | 25.30" | 10.43" | −1.2% | 59.3 mph | Compare |
| 225/45R18 | 25.97" | 8.86" | +1.4% | 60.8 mph | Compare |
| 205/45R18 | 25.26" | 8.07" | −1.4% | 59.2 mph | Compare |
| 255/40R18 | 26.03" | 10.04" | +1.6% | 61.0 mph | Compare |
| 205/50R18 | 26.07" | 8.07" | +1.8% | 61.1 mph | Compare |
| 295/35R18 | 26.13" | 11.61" | +2.0% | 61.2 mph | Compare |
| 225/40R18 | 25.09" | 8.86" | −2.1% | 58.8 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 235/25R21 | 21" | 25.63" | 0.0% | Compare |
| 245/55R15 | 15" | 25.61" | 0.0% | Compare |
| 285/25R20 | 20" | 25.61" | 0.0% | Compare |
| 225/60R15 | 15" | 25.63" | 0.0% | Compare |
| 335/25R19 | 19" | 25.59" | −0.1% | Compare |
| 175/70R16 | 16" | 25.65" | +0.1% | Compare |
| 245/50R16 | 16" | 25.65" | +0.1% | Compare |
| 185/80R14 | 14" | 25.65" | +0.1% | Compare |
| 275/40R17 | 17" | 25.66" | +0.2% | Compare |
| 245/60R14 | 14" | 25.57" | −0.2% | Compare |
| 245/45R17 | 17" | 25.68" | +0.2% | Compare |
| 315/35R17 | 17" | 25.68" | +0.2% | Compare |
One size up or down
- 205/45R18narrower: 25.3" × 8.1"
- 225/45R18wider: 26.0" × 8.9"
- 215/40R18lower profile: 24.8" × 8.5"
- 215/50R18taller sidewall: 26.5" × 8.5"
Compare 215/45R18 with another size
Questions
- How tall is a 215/45R18 tire?
- A 215/45R18 tire is 25.6 inches tall (651 mm), calculated from the size. It is 8.5 inches wide with 3.8 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 215/45R18 mean?
- 215/45R18 means a tire 215 mm wide, with sidewalls 45% as tall as the tire is wide (97 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 215/45R18 tire make?
- About 787 revolutions per mile, based on a circumference of 80.5 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 215/45R18 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 275/35R18 instead of 215/45R18?
- 275/35R18 is −0.04 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.