205/55R18 tire size in inches
A 205/55R18 tire measures
26.9" tall × 8.1" wide
4.44" sidewall on a 18" wheel. 750 revolutions per mile.
205/55R18 means a tire 205 mm wide, with sidewalls 55% as tall as the tire is wide (113 mm), radial construction (R), for a 18 inch wheel.
205/55R18 specs
| Overall diameter (height) | 26.88 inches (683 mm) |
|---|---|
| Section width | 8.07 inches (205 mm) |
| Sidewall height | 4.44 inches (113 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 84.4 inches (2,145 mm) |
| Revolutions per mile | 750 |
| Revolutions per kilometer | 466 |
| Approximate rim width | 6.0" to 7.5" |
| In inches (flotation style) | 26.9x8.1R18 |
| Aspect ratio | 55% |
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 205/55R18 on a 18" wheel
These 18" sizes are within 3% of 205/55R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 225/50R18 | 26.86" | 8.86" | −0.1% | 60.0 mph | Compare |
| 325/35R18 | 26.96" | 12.80" | +0.3% | 60.2 mph | Compare |
| 285/40R18 | 26.98" | 11.22" | +0.4% | 60.2 mph | Compare |
| 255/45R18 | 27.04" | 10.04" | +0.6% | 60.4 mph | Compare |
| 245/45R18 | 26.68" | 9.65" | −0.7% | 59.6 mph | Compare |
| 315/35R18 | 26.68" | 12.40" | −0.7% | 59.6 mph | Compare |
| 275/40R18 | 26.66" | 10.83" | −0.8% | 59.5 mph | Compare |
| 195/60R18 | 27.21" | 7.68" | +1.2% | 60.7 mph | Compare |
| 335/35R18 | 27.23" | 13.19" | +1.3% | 60.8 mph | Compare |
| 235/50R18 | 27.25" | 9.25" | +1.4% | 60.8 mph | Compare |
| 215/50R18 | 26.46" | 8.46" | −1.5% | 59.1 mph | Compare |
| 295/40R18 | 27.29" | 11.61" | +1.5% | 60.9 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 235/75R13 | 13" | 26.88" | 0.0% | Compare |
| 285/35R19 | 19" | 26.85" | −0.1% | Compare |
| 215/70R15 | 15" | 26.85" | −0.1% | Compare |
| 275/55R15 | 15" | 26.91" | +0.1% | Compare |
| 205/80R14 | 14" | 26.91" | +0.1% | Compare |
| 335/30R19 | 19" | 26.91" | +0.1% | Compare |
| 315/40R17 | 17" | 26.92" | +0.2% | Compare |
| 185/75R16 | 16" | 26.93" | +0.2% | Compare |
| 275/50R16 | 16" | 26.83" | −0.2% | Compare |
| 245/25R22 | 22" | 26.82" | −0.2% | Compare |
| 295/25R21 | 21" | 26.81" | −0.3% | Compare |
| 235/70R14 | 14" | 26.95" | +0.3% | Compare |
One size up or down
- 195/55R18narrower: 26.4" × 7.7"
- 215/55R18wider: 27.3" × 8.5"
- 205/50R18lower profile: 26.1" × 8.1"
- 205/60R18taller sidewall: 27.7" × 8.1"
Compare 205/55R18 with another size
Questions
- How tall is a 205/55R18 tire?
- A 205/55R18 tire is 26.9 inches tall (683 mm), calculated from the size. It is 8.1 inches wide with 4.4 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 205/55R18 mean?
- 205/55R18 means a tire 205 mm wide, with sidewalls 55% as tall as the tire is wide (113 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 205/55R18 tire make?
- About 750 revolutions per mile, based on a circumference of 84.4 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 205/55R18 tire?
- Roughly 6.0" to 7.5". Check the tire maker's approved rim range for the exact model before buying wheels.
- Can I use 225/50R18 instead of 205/55R18?
- 225/50R18 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.