205/70R18 tire size in inches
A 205/70R18 tire measures
29.3" tall × 8.1" wide
5.65" sidewall on a 18" wheel. 688 revolutions per mile.
205/70R18 means a tire 205 mm wide, with sidewalls 70% as tall as the tire is wide (144 mm), radial construction (R), for a 18 inch wheel.
205/70R18 specs
| Overall diameter (height) | 29.30 inches (744 mm) |
|---|---|
| Section width | 8.07 inches (205 mm) |
| Sidewall height | 5.65 inches (144 mm) |
| Wheel (rim) diameter | 18 inches |
| Circumference | 92.0 inches (2,338 mm) |
| Revolutions per mile | 688 |
| Revolutions per kilometer | 428 |
| Approximate rim width | 5.5" to 7.0" |
| In inches (flotation style) | 29.3x8.1R18 |
| Aspect ratio | 70% |
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 205/70R18 on a 18" wheel
These 18" sizes are within 3% of 205/70R18's overall diameter, the range most tire shops treat as interchangeable.
| Size | Diameter | Width | Difference | Real speed at 60 | |
|---|---|---|---|---|---|
| 285/50R18 | 29.22" | 11.22" | −0.3% | 59.8 mph | Compare |
| 315/45R18 | 29.16" | 12.40" | −0.5% | 59.7 mph | Compare |
| 265/55R18 | 29.48" | 10.43" | +0.6% | 60.4 mph | Compare |
| 235/60R18 | 29.10" | 9.25" | −0.7% | 59.6 mph | Compare |
| 195/75R18 | 29.52" | 7.68" | +0.7% | 60.4 mph | Compare |
| 225/65R18 | 29.52" | 8.86" | +0.7% | 60.4 mph | Compare |
| 325/45R18 | 29.52" | 12.80" | +0.7% | 60.4 mph | Compare |
| 255/55R18 | 29.04" | 10.04" | −0.9% | 59.5 mph | Compare |
| 245/60R18 | 29.57" | 9.65" | +0.9% | 60.6 mph | Compare |
| 215/65R18 | 29.00" | 8.46" | −1.0% | 59.4 mph | Compare |
| 295/50R18 | 29.61" | 11.61" | +1.1% | 60.6 mph | Compare |
| 275/50R18 | 28.83" | 10.83" | −1.6% | 59.0 mph | Compare |
Same height on other wheel sizes (plus and minus sizing)
| Size | Wheel | Diameter | Difference | |
|---|---|---|---|---|
| 265/35R22 | 22" | 29.30" | 0.0% | Compare |
| 295/40R20 | 20" | 29.29" | 0.0% | Compare |
| 215/55R20 | 20" | 29.31" | 0.0% | Compare |
| 225/75R16 | 16" | 29.29" | 0.0% | Compare |
| 235/45R21 | 21" | 29.33" | +0.1% | Compare |
| 285/55R17 | 17" | 29.34" | +0.1% | Compare |
| 265/40R21 | 21" | 29.35" | +0.2% | Compare |
| 235/50R20 | 20" | 29.25" | −0.2% | Compare |
| 325/40R19 | 19" | 29.24" | −0.2% | Compare |
| 335/35R20 | 20" | 29.23" | −0.2% | Compare |
| 265/25R24 | 24" | 29.22" | −0.3% | Compare |
| 355/30R21 | 21" | 29.39" | +0.3% | Compare |
One size up or down
- 195/70R18narrower: 28.7" × 7.7"
- 215/70R18wider: 29.9" × 8.5"
- 205/65R18lower profile: 28.5" × 8.1"
- 205/75R18taller sidewall: 30.1" × 8.1"
Compare 205/70R18 with another size
Questions
- How tall is a 205/70R18 tire?
- A 205/70R18 tire is 29.3 inches tall (744 mm), calculated from the size. It is 8.1 inches wide with 5.6 inches sidewalls. Real tires vary by a few tenths of an inch between brands and tread patterns.
- What does 205/70R18 mean?
- 205/70R18 means a tire 205 mm wide, with sidewalls 70% as tall as the tire is wide (144 mm), radial construction (R), for a 18 inch wheel.
- How many revolutions per mile does a 205/70R18 tire make?
- About 688 revolutions per mile, based on a circumference of 92.0 inches. Under load the tire flattens slightly, so the maker's published figure is usually a little higher.
- What rim width fits a 205/70R18 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 285/50R18 instead of 205/70R18?
- 285/50R18 is −0.08 inches (−0.3%) in overall diameter, so at an indicated 60 mph you would be doing 59.8 mph. Differences under 3% are usually fine, but check clearance, load index and your vehicle's placard.