245/70R18 tire size in inches
A 245/70R18 tire measures
31.5" tall × 9.6" wide
6.75" sidewall on a 18" wheel. 640 revolutions per mile.
245/70R18 means a tire 245 mm wide, with sidewalls 70% as tall as the tire is wide (172 mm), radial construction (R), for a 18 inch wheel.
245/70R18 specs
| Overall diameter (height) | 31.50 inches (800 mm) |
|---|---|
| Section width | 9.65 inches (245 mm) |
| Sidewall height | 6.75 inches (172 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 99.0 inches (2,514 mm) |
| Revolutions per mile | 640 |
| Revolutions per kilometer | 398 |
| Approximate rim width | 6.5" to 8.0" |
| In inches (flotation style) | 31.5x9.6R18 |
| 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 245/70R18 on a 18" wheel
These 18" sizes are within 3% of 245/70R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 285/60R18 | 31.46" | 11.22" | −0.1% | 59.9 mph | Compare |
| 265/65R18 | 31.56" | 10.43" | +0.2% | 60.1 mph | Compare |
| 315/55R18 | 31.64" | 12.40" | +0.4% | 60.3 mph | Compare |
| 225/75R18 | 31.29" | 8.86" | −0.7% | 59.6 mph | Compare |
| 305/55R18 | 31.21" | 12.01" | −0.9% | 59.4 mph | Compare |
| 335/50R18 | 31.19" | 13.19" | −1.0% | 59.4 mph | Compare |
| 235/75R18 | 31.88" | 9.25" | +1.2% | 60.7 mph | Compare |
| 295/60R18 | 31.94" | 11.61" | +1.4% | 60.8 mph | Compare |
| 255/65R18 | 31.05" | 10.04" | −1.4% | 59.1 mph | Compare |
| 275/60R18 | 30.99" | 10.83" | −1.6% | 59.0 mph | Compare |
| 235/70R18 | 30.95" | 9.25" | −1.7% | 59.0 mph | Compare |
| 255/70R18 | 32.06" | 10.04" | +1.7% | 61.0 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 345/35R22 | 22" | 31.51" | 0.0% | Compare |
| 225/65R20 | 20" | 31.52" | 0.0% | Compare |
| 325/45R20 | 20" | 31.52" | 0.0% | Compare |
| 265/60R19 | 19" | 31.52" | 0.0% | Compare |
| 265/55R20 | 20" | 31.48" | −0.1% | Compare |
| 245/75R17 | 17" | 31.47" | −0.1% | Compare |
| 245/65R19 | 19" | 31.54" | +0.1% | Compare |
| 335/40R21 | 21" | 31.55" | +0.1% | Compare |
| 295/45R21 | 21" | 31.45" | −0.2% | Compare |
| 315/30R24 | 24" | 31.44" | −0.2% | Compare |
| 245/80R16 | 16" | 31.43" | −0.2% | Compare |
| 265/50R21 | 21" | 31.43" | −0.2% | Compare |
One size up or down
- 235/70R18narrower: 31.0" × 9.3"
- 255/70R18wider: 32.1" × 10.0"
- 245/65R18lower profile: 30.5" × 9.6"
- 245/75R18taller sidewall: 32.5" × 9.6"
Compare 245/70R18 with another size
Questions
- How tall is a 245/70R18 tire?
- A 245/70R18 tire is 31.5 inches tall (800 mm), calculated from the size. It is 9.6 inches wide with 6.8 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 245/70R18 mean?
- 245/70R18 means a tire 245 mm wide, with sidewalls 70% as tall as the tire is wide (172 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 245/70R18 tire make?
- About 640 revolutions per mile, based on a circumference of 99.0 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 245/70R18 tire?
- Roughly 6.5" to 8.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 285/60R18 instead of 245/70R18?
- 285/60R18 is −0.04 inches (−0.1%) 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.