215/75R18 tire size in inches
A 215/75R18 tire measures
30.7" tall × 8.5" wide
6.35" sidewall on a 18" wheel. 657 revolutions per mile.
215/75R18 means a tire 215 mm wide, with sidewalls 75% as tall as the tire is wide (161 mm), radial construction (R), for a 18 inch wheel.
215/75R18 specs
| Overall diameter (height) | 30.70 inches (780 mm) |
|---|---|
| Section width | 8.46 inches (215 mm) |
| Sidewall height | 6.35 inches (161 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 96.4 inches (2,449 mm) |
| Revolutions per mile | 657 |
| Revolutions per kilometer | 408 |
| Approximate rim width | 5.5" to 7.0" |
| In inches (flotation style) | 30.7x8.5R18 |
| Aspect ratio | 75% |
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 215/75R18 on a 18" wheel
These 18" sizes are within 3% of 215/75R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 295/55R18 | 30.78" | 11.61" | +0.3% | 60.2 mph | Compare |
| 325/50R18 | 30.80" | 12.80" | +0.3% | 60.2 mph | Compare |
| 245/65R18 | 30.54" | 9.65" | −0.5% | 59.7 mph | Compare |
| 265/60R18 | 30.52" | 10.43" | −0.6% | 59.7 mph | Compare |
| 235/70R18 | 30.95" | 9.25" | +0.8% | 60.5 mph | Compare |
| 225/70R18 | 30.40" | 8.86" | −1.0% | 59.4 mph | Compare |
| 275/60R18 | 30.99" | 10.83" | +1.0% | 60.6 mph | Compare |
| 315/50R18 | 30.40" | 12.40" | −1.0% | 59.4 mph | Compare |
| 255/65R18 | 31.05" | 10.04" | +1.2% | 60.7 mph | Compare |
| 285/55R18 | 30.34" | 11.22" | −1.2% | 59.3 mph | Compare |
| 335/50R18 | 31.19" | 13.19" | +1.6% | 61.0 mph | Compare |
| 305/55R18 | 31.21" | 12.01" | +1.7% | 61.0 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 265/80R14 | 14" | 30.69" | 0.0% | Compare |
| 285/70R15 | 15" | 30.71" | 0.0% | Compare |
| 245/45R22 | 22" | 30.68" | −0.1% | Compare |
| 315/35R22 | 22" | 30.68" | −0.1% | Compare |
| 235/85R15 | 15" | 30.73" | +0.1% | Compare |
| 285/30R24 | 24" | 30.73" | +0.1% | Compare |
| 275/40R22 | 22" | 30.66" | −0.1% | Compare |
| 225/55R21 | 21" | 30.74" | +0.2% | Compare |
| 265/75R15 | 15" | 30.65" | −0.2% | Compare |
| 275/45R21 | 21" | 30.74" | +0.2% | Compare |
| 245/50R21 | 21" | 30.65" | −0.2% | Compare |
| 315/55R17 | 17" | 30.64" | −0.2% | Compare |
One size up or down
Compare 215/75R18 with another size
Questions
- How tall is a 215/75R18 tire?
- A 215/75R18 tire is 30.7 inches tall (780 mm), calculated from the size. It is 8.5 inches wide with 6.3 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 215/75R18 mean?
- 215/75R18 means a tire 215 mm wide, with sidewalls 75% as tall as the tire is wide (161 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 215/75R18 tire make?
- About 657 revolutions per mile, based on a circumference of 96.4 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 215/75R18 tire?
- Roughly 5.5" to 7.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 295/55R18 instead of 215/75R18?
- 295/55R18 is +0.08 inches (+0.3%) in overall diameter, so at an indicated 60 mph you would be doing 60.2 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.