235/70R18 tire size in inches
A 235/70R18 tire measures
31.0" tall × 9.3" wide
6.48" sidewall on a 18" wheel. 652 revolutions per mile.
235/70R18 means a tire 235 mm wide, with sidewalls 70% as tall as the tire is wide (165 mm), radial construction (R), for a 18 inch wheel.
235/70R18 specs
| Overall diameter (height) | 30.95 inches (786 mm) |
|---|---|
| Section width | 9.25 inches (235 mm) |
| Sidewall height | 6.48 inches (165 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 97.2 inches (2,470 mm) |
| Revolutions per mile | 652 |
| Revolutions per kilometer | 405 |
| Approximate rim width | 6.0" to 7.5" |
| In inches (flotation style) | 31.0x9.3R18 |
| Aspect ratio | 70% |
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 235/70R18 on a 18" wheel
These 18" sizes are within 3% of 235/70R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 275/60R18 | 30.99" | 10.83" | +0.1% | 60.1 mph | Compare |
| 255/65R18 | 31.05" | 10.04" | +0.3% | 60.2 mph | Compare |
| 325/50R18 | 30.80" | 12.80" | −0.5% | 59.7 mph | Compare |
| 295/55R18 | 30.78" | 11.61" | −0.6% | 59.7 mph | Compare |
| 335/50R18 | 31.19" | 13.19" | +0.8% | 60.5 mph | Compare |
| 215/75R18 | 30.70" | 8.46" | −0.8% | 59.5 mph | Compare |
| 305/55R18 | 31.21" | 12.01" | +0.8% | 60.5 mph | Compare |
| 225/75R18 | 31.29" | 8.86" | +1.1% | 60.6 mph | Compare |
| 245/65R18 | 30.54" | 9.65" | −1.3% | 59.2 mph | Compare |
| 265/60R18 | 30.52" | 10.43" | −1.4% | 59.2 mph | Compare |
| 285/60R18 | 31.46" | 11.22" | +1.7% | 61.0 mph | Compare |
| 225/70R18 | 30.40" | 8.86" | −1.8% | 58.9 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 325/35R22 | 22" | 30.96" | 0.0% | Compare |
| 295/60R17 | 17" | 30.94" | −0.1% | Compare |
| 295/30R24 | 24" | 30.97" | +0.1% | Compare |
| 285/40R22 | 22" | 30.98" | +0.1% | Compare |
| 315/40R21 | 21" | 30.92" | −0.1% | Compare |
| 355/25R24 | 24" | 30.99" | +0.1% | Compare |
| 275/55R19 | 19" | 30.91" | −0.1% | Compare |
| 31x10.50R15 | 15" | 31.00" | +0.2% | Compare |
| 215/65R20 | 20" | 31.00" | +0.2% | Compare |
| 305/50R19 | 19" | 31.01" | +0.2% | Compare |
| 235/75R17 | 17" | 30.88" | −0.2% | Compare |
| 235/65R19 | 19" | 31.03" | +0.2% | Compare |
One size up or down
- 225/70R18narrower: 30.4" × 8.9"
- 245/70R18wider: 31.5" × 9.6"
- 235/65R18lower profile: 30.0" × 9.3"
- 235/75R18taller sidewall: 31.9" × 9.3"
Compare 235/70R18 with another size
Questions
- How tall is a 235/70R18 tire?
- A 235/70R18 tire is 31.0 inches tall (786 mm), calculated from the size. It is 9.3 inches wide with 6.5 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 235/70R18 mean?
- 235/70R18 means a tire 235 mm wide, with sidewalls 70% as tall as the tire is wide (165 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 235/70R18 tire make?
- About 652 revolutions per mile, based on a circumference of 97.2 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 235/70R18 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 275/60R18 instead of 235/70R18?
- 275/60R18 is +0.04 inches (+0.1%) 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.