325/50R18 tire size in inches
A 325/50R18 tire measures
30.8" tall × 12.8" wide
6.40" sidewall on a 18" wheel. 655 revolutions per mile.
325/50R18 means a tire 325 mm wide, with sidewalls 50% as tall as the tire is wide (163 mm), radial construction (R), for a 18 inch wheel.
325/50R18 specs
| Overall diameter (height) | 30.80 inches (782 mm) |
|---|---|
| Section width | 12.80 inches (325 mm) |
| Sidewall height | 6.40 inches (163 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 96.7 inches (2,457 mm) |
| Revolutions per mile | 655 |
| Revolutions per kilometer | 407 |
| Approximate rim width | 9.5" to 11.0" |
| In inches (flotation style) | 30.8x12.8R18 |
| Aspect ratio | 50% |
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 325/50R18 on a 18" wheel
These 18" sizes are within 3% of 325/50R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 295/55R18 | 30.78" | 11.61" | −0.1% | 60.0 mph | Compare |
| 215/75R18 | 30.70" | 8.46" | −0.3% | 59.8 mph | Compare |
| 235/70R18 | 30.95" | 9.25" | +0.5% | 60.3 mph | Compare |
| 275/60R18 | 30.99" | 10.83" | +0.6% | 60.4 mph | Compare |
| 245/65R18 | 30.54" | 9.65" | −0.8% | 59.5 mph | Compare |
| 255/65R18 | 31.05" | 10.04" | +0.8% | 60.5 mph | Compare |
| 265/60R18 | 30.52" | 10.43" | −0.9% | 59.5 mph | Compare |
| 225/70R18 | 30.40" | 8.86" | −1.3% | 59.2 mph | Compare |
| 315/50R18 | 30.40" | 12.40" | −1.3% | 59.2 mph | Compare |
| 335/50R18 | 31.19" | 13.19" | +1.3% | 60.8 mph | Compare |
| 305/55R18 | 31.21" | 12.01" | +1.3% | 60.8 mph | Compare |
| 285/55R18 | 30.34" | 11.22" | −1.5% | 59.1 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 345/25R24 | 24" | 30.79" | 0.0% | Compare |
| 235/80R16 | 16" | 30.80" | 0.0% | Compare |
| 305/45R20 | 20" | 30.81" | 0.0% | Compare |
| 355/35R21 | 21" | 30.78" | 0.0% | Compare |
| 275/50R20 | 20" | 30.83" | +0.1% | Compare |
| 225/55R21 | 21" | 30.74" | −0.2% | Compare |
| 275/45R21 | 21" | 30.74" | −0.2% | Compare |
| 285/30R24 | 24" | 30.73" | −0.2% | Compare |
| 235/85R15 | 15" | 30.73" | −0.2% | Compare |
| 345/40R20 | 20" | 30.87" | +0.2% | Compare |
| 335/45R19 | 19" | 30.87" | +0.2% | Compare |
| 235/75R17 | 17" | 30.88" | +0.3% | Compare |
One size up or down
- 315/50R18narrower: 30.4" × 12.4"
- 335/50R18wider: 31.2" × 13.2"
- 325/45R18lower profile: 29.5" × 12.8"
- 325/55R18taller sidewall: 32.1" × 12.8"
Compare 325/50R18 with another size
Questions
- How tall is a 325/50R18 tire?
- A 325/50R18 tire is 30.8 inches tall (782 mm), calculated from the size. It is 12.8 inches wide with 6.4 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 325/50R18 mean?
- 325/50R18 means a tire 325 mm wide, with sidewalls 50% as tall as the tire is wide (163 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 325/50R18 tire make?
- About 655 revolutions per mile, based on a circumference of 96.7 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 325/50R18 tire?
- Roughly 9.5" to 11.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 295/55R18 instead of 325/50R18?
- 295/55R18 is −0.02 inches (−0.1%) in overall diameter, so at an indicated 60 mph you would be doing 60.0 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.