205/75R18 tire size in inches
A 205/75R18 tire measures
30.1" tall × 8.1" wide
6.05" sidewall on a 18" wheel. 670 revolutions per mile.
205/75R18 means a tire 205 mm wide, with sidewalls 75% as tall as the tire is wide (154 mm), radial construction (R), for a 18 inch wheel.
205/75R18 specs
| Overall diameter (height) | 30.11 inches (765 mm) |
|---|---|
| Section width | 8.07 inches (205 mm) |
| Sidewall height | 6.05 inches (154 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 94.6 inches (2,402 mm) |
| Revolutions per mile | 670 |
| Revolutions per kilometer | 416 |
| Approximate rim width | 5.5" to 7.0" |
| In inches (flotation style) | 30.1x8.1R18 |
| Aspect ratio | 75% |
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 205/75R18 on a 18" wheel
These 18" sizes are within 3% of 205/75R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 255/60R18 | 30.05" | 10.04" | −0.2% | 59.9 mph | Compare |
| 235/65R18 | 30.03" | 9.25" | −0.3% | 59.8 mph | Compare |
| 305/50R18 | 30.01" | 12.01" | −0.3% | 59.8 mph | Compare |
| 275/55R18 | 29.91" | 10.83" | −0.7% | 59.6 mph | Compare |
| 285/55R18 | 30.34" | 11.22" | +0.8% | 60.5 mph | Compare |
| 335/45R18 | 29.87" | 13.19" | −0.8% | 59.5 mph | Compare |
| 215/70R18 | 29.85" | 8.46" | −0.9% | 59.5 mph | Compare |
| 225/70R18 | 30.40" | 8.86" | +1.0% | 60.6 mph | Compare |
| 315/50R18 | 30.40" | 12.40" | +1.0% | 60.6 mph | Compare |
| 265/60R18 | 30.52" | 10.43" | +1.4% | 60.8 mph | Compare |
| 245/65R18 | 30.54" | 9.65" | +1.4% | 60.9 mph | Compare |
| 295/50R18 | 29.61" | 11.61" | −1.6% | 59.0 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 235/60R19 | 19" | 30.10" | 0.0% | Compare |
| 285/45R20 | 20" | 30.10" | 0.0% | Compare |
| 295/35R22 | 22" | 30.13" | +0.1% | Compare |
| 275/65R16 | 16" | 30.07" | −0.1% | Compare |
| 255/80R14 | 14" | 30.06" | −0.1% | Compare |
| 345/30R22 | 22" | 30.15" | +0.1% | Compare |
| 225/85R15 | 15" | 30.06" | −0.2% | Compare |
| 255/75R15 | 15" | 30.06" | −0.2% | Compare |
| 215/60R20 | 20" | 30.16" | +0.2% | Compare |
| 255/70R16 | 16" | 30.06" | −0.2% | Compare |
| 275/70R15 | 15" | 30.16" | +0.2% | Compare |
| 255/65R17 | 17" | 30.05" | −0.2% | Compare |
One size up or down
Compare 205/75R18 with another size
Questions
- How tall is a 205/75R18 tire?
- A 205/75R18 tire is 30.1 inches tall (765 mm), calculated from the size. It is 8.1 inches wide with 6.1 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 205/75R18 mean?
- 205/75R18 means a tire 205 mm wide, with sidewalls 75% as tall as the tire is wide (154 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 205/75R18 tire make?
- About 670 revolutions per mile, based on a circumference of 94.6 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 205/75R18 tire?
- Roughly 5.5" to 7.0". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 255/60R18 instead of 205/75R18?
- 255/60R18 is −0.06 inches (−0.2%) 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.