325/65R18 tire size in inches
A 325/65R18 tire measures
34.6" tall × 12.8" wide
8.32" sidewall on a 18" wheel. 582 revolutions per mile.
325/65R18 means a tire 325 mm wide, with sidewalls 65% as tall as the tire is wide (211 mm), radial construction (R), for a 18 inch wheel.
325/65R18 specs
| Overall diameter (height) | 34.63 inches (880 mm) |
|---|---|
| Section width | 12.80 inches (325 mm) |
| Sidewall height | 8.32 inches (211 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 108.8 inches (2,764 mm) |
| Revolutions per mile | 582 |
| Revolutions per kilometer | 362 |
| Approximate rim width | 8.5" to 10.0" |
| In inches (flotation style) | 34.6x12.8R18 |
| 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 325/65R18 on a 18" wheel
These 18" sizes are within 3% of 325/65R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 305/70R18 | 34.81" | 12.01" | +0.5% | 60.3 mph | Compare |
| 285/75R18 | 34.83" | 11.22" | +0.6% | 60.3 mph | Compare |
| 35x12.50R18 | 35.00" | 12.50" | +1.1% | 60.6 mph | Compare |
| 295/70R18 | 34.26" | 11.61" | −1.1% | 59.4 mph | Compare |
| 275/75R18 | 34.24" | 10.83" | −1.1% | 59.3 mph | Compare |
| 315/65R18 | 34.12" | 12.40" | −1.5% | 59.1 mph | Compare |
| 335/65R18 | 35.15" | 13.19" | +1.5% | 60.9 mph | Compare |
| 315/70R18 | 35.36" | 12.40" | +2.1% | 61.3 mph | Compare |
| 295/75R18 | 35.42" | 11.61" | +2.3% | 61.4 mph | Compare |
| 335/60R18 | 33.83" | 13.19" | −2.3% | 58.6 mph | Compare |
| 285/70R18 | 33.71" | 11.22" | −2.7% | 58.4 mph | Compare |
| 265/75R18 | 33.65" | 10.43" | −2.8% | 58.3 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 315/55R21 | 21" | 34.64" | 0.0% | Compare |
| 305/65R19 | 19" | 34.61" | −0.1% | Compare |
| 285/65R20 | 20" | 34.59" | −0.1% | Compare |
| 295/80R16 | 16" | 34.58" | −0.1% | Compare |
| 345/50R21 | 21" | 34.58" | −0.1% | Compare |
| 355/45R22 | 22" | 34.58" | −0.2% | Compare |
| 335/40R24 | 24" | 34.55" | −0.2% | Compare |
| 335/55R20 | 20" | 34.51" | −0.4% | Compare |
| 295/55R22 | 22" | 34.78" | +0.4% | Compare |
| 325/50R22 | 22" | 34.80" | +0.5% | Compare |
| 335/60R19 | 19" | 34.83" | +0.6% | Compare |
| 295/75R17 | 17" | 34.42" | −0.6% | Compare |
One size up or down
- 315/65R18narrower: 34.1" × 12.4"
- 335/65R18wider: 35.1" × 13.2"
- 325/60R18lower profile: 33.4" × 12.8"
- 325/70R18taller sidewall: 35.9" × 12.8"
Compare 325/65R18 with another size
Questions
- How tall is a 325/65R18 tire?
- A 325/65R18 tire is 34.6 inches tall (880 mm), calculated from the size. It is 12.8 inches wide with 8.3 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 325/65R18 mean?
- 325/65R18 means a tire 325 mm wide, with sidewalls 65% as tall as the tire is wide (211 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 325/65R18 tire make?
- About 582 revolutions per mile, based on a circumference of 108.8 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 325/65R18 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 305/70R18 instead of 325/65R18?
- 305/70R18 is +0.18 inches (+0.5%) in overall diameter, so at an indicated 60 mph you would be doing 60.3 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.