315/65R18 tire size in inches
A 315/65R18 tire measures
34.1" tall × 12.4" wide
8.06" sidewall on a 18" wheel. 591 revolutions per mile.
315/65R18 means a tire 315 mm wide, with sidewalls 65% as tall as the tire is wide (205 mm), radial construction (R), for a 18 inch wheel.
315/65R18 specs
| Overall diameter (height) | 34.12 inches (867 mm) |
|---|---|
| Section width | 12.40 inches (315 mm) |
| Sidewall height | 8.06 inches (205 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 107.2 inches (2,723 mm) |
| Revolutions per mile | 591 |
| Revolutions per kilometer | 367 |
| Approximate rim width | 8.5" to 10.0" |
| In inches (flotation style) | 34.1x12.4R18 |
| Aspect ratio | 65% |
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 315/65R18 on a 18" wheel
These 18" sizes are within 3% of 315/65R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 275/75R18 | 34.24" | 10.83" | +0.3% | 60.2 mph | Compare |
| 295/70R18 | 34.26" | 11.61" | +0.4% | 60.2 mph | Compare |
| 335/60R18 | 33.83" | 13.19" | −0.9% | 59.5 mph | Compare |
| 285/70R18 | 33.71" | 11.22" | −1.2% | 59.3 mph | Compare |
| 265/75R18 | 33.65" | 10.43" | −1.4% | 59.2 mph | Compare |
| 305/65R18 | 33.61" | 12.01" | −1.5% | 59.1 mph | Compare |
| 325/65R18 | 34.63" | 12.80" | +1.5% | 60.9 mph | Compare |
| 305/70R18 | 34.81" | 12.01" | +2.0% | 61.2 mph | Compare |
| 285/75R18 | 34.83" | 11.22" | +2.1% | 61.2 mph | Compare |
| 325/60R18 | 33.35" | 12.80" | −2.2% | 58.7 mph | Compare |
| 35x12.50R18 | 35.00" | 12.50" | +2.6% | 61.5 mph | Compare |
| 275/70R18 | 33.16" | 10.83" | −2.8% | 58.3 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 295/65R19 | 19" | 34.10" | −0.1% | Compare |
| 275/65R20 | 20" | 34.07" | −0.1% | Compare |
| 285/85R15 | 15" | 34.07" | −0.1% | Compare |
| 325/55R20 | 20" | 34.07" | −0.1% | Compare |
| 335/50R21 | 21" | 34.19" | +0.2% | Compare |
| 305/55R21 | 21" | 34.21" | +0.3% | Compare |
| 345/45R22 | 22" | 34.22" | +0.3% | Compare |
| 305/50R22 | 22" | 34.01" | −0.3% | Compare |
| 325/40R24 | 24" | 34.24" | +0.3% | Compare |
| 355/50R20 | 20" | 33.98" | −0.4% | Compare |
| 285/80R16 | 16" | 33.95" | −0.5% | Compare |
| 345/55R19 | 19" | 33.94" | −0.5% | Compare |
One size up or down
- 305/65R18narrower: 33.6" × 12.0"
- 325/65R18wider: 34.6" × 12.8"
- 315/60R18lower profile: 32.9" × 12.4"
- 315/70R18taller sidewall: 35.4" × 12.4"
Compare 315/65R18 with another size
Questions
- How tall is a 315/65R18 tire?
- A 315/65R18 tire is 34.1 inches tall (867 mm), calculated from the size. It is 12.4 inches wide with 8.1 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 315/65R18 mean?
- 315/65R18 means a tire 315 mm wide, with sidewalls 65% as tall as the tire is wide (205 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 315/65R18 tire make?
- About 591 revolutions per mile, based on a circumference of 107.2 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 315/65R18 tire?
- Roughly 8.5" to 10.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 275/75R18 instead of 315/65R18?
- 275/75R18 is +0.12 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.