235/75R18 tire size in inches
A 235/75R18 tire measures
31.9" tall × 9.3" wide
6.94" sidewall on a 18" wheel. 633 revolutions per mile.
235/75R18 means a tire 235 mm wide, with sidewalls 75% as tall as the tire is wide (176 mm), radial construction (R), for a 18 inch wheel.
235/75R18 specs
| Overall diameter (height) | 31.88 inches (810 mm) |
|---|---|
| Section width | 9.25 inches (235 mm) |
| Sidewall height | 6.94 inches (176 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 100.1 inches (2,544 mm) |
| Revolutions per mile | 633 |
| Revolutions per kilometer | 393 |
| Approximate rim width | 6.0" to 7.5" |
| In inches (flotation style) | 31.9x9.3R18 |
| 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 235/75R18 on a 18" wheel
These 18" sizes are within 3% of 235/75R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 295/60R18 | 31.94" | 11.61" | +0.2% | 60.1 mph | Compare |
| 255/70R18 | 32.06" | 10.04" | +0.6% | 60.3 mph | Compare |
| 275/65R18 | 32.07" | 10.83" | +0.6% | 60.4 mph | Compare |
| 325/55R18 | 32.07" | 12.80" | +0.6% | 60.4 mph | Compare |
| 315/55R18 | 31.64" | 12.40" | −0.7% | 59.6 mph | Compare |
| 265/65R18 | 31.56" | 10.43" | −1.0% | 59.4 mph | Compare |
| 245/70R18 | 31.50" | 9.65" | −1.2% | 59.3 mph | Compare |
| 285/60R18 | 31.46" | 11.22" | −1.3% | 59.2 mph | Compare |
| 305/60R18 | 32.41" | 12.01" | +1.7% | 61.0 mph | Compare |
| 225/75R18 | 31.29" | 8.86" | −1.9% | 58.9 mph | Compare |
| 245/75R18 | 32.47" | 9.65" | +1.9% | 61.1 mph | Compare |
| 335/55R18 | 32.51" | 13.19" | +2.0% | 61.2 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 315/60R17 | 17" | 31.88" | 0.0% | Compare |
| 335/45R20 | 20" | 31.87" | 0.0% | Compare |
| 345/40R21 | 21" | 31.87" | 0.0% | Compare |
| 285/35R24 | 24" | 31.85" | −0.1% | Compare |
| 275/55R20 | 20" | 31.91" | +0.1% | Compare |
| 335/30R24 | 24" | 31.91" | +0.1% | Compare |
| 315/40R22 | 22" | 31.92" | +0.1% | Compare |
| 285/75R15 | 15" | 31.83" | −0.1% | Compare |
| 275/50R21 | 21" | 31.83" | −0.2% | Compare |
| 305/45R21 | 21" | 31.81" | −0.2% | Compare |
| 325/50R19 | 19" | 31.80" | −0.3% | Compare |
| 355/35R22 | 22" | 31.78" | −0.3% | Compare |
One size up or down
Compare 235/75R18 with another size
Questions
- How tall is a 235/75R18 tire?
- A 235/75R18 tire is 31.9 inches tall (810 mm), calculated from the size. It is 9.3 inches wide with 6.9 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 235/75R18 mean?
- 235/75R18 means a tire 235 mm wide, with sidewalls 75% as tall as the tire is wide (176 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 235/75R18 tire make?
- About 633 revolutions per mile, based on a circumference of 100.1 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 235/75R18 tire?
- Roughly 6.0" to 7.5". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 295/60R18 instead of 235/75R18?
- 295/60R18 is +0.06 inches (+0.2%) in overall diameter, so at an indicated 60 mph you would be doing 60.1 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.