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285/70R18 tire size in inches
285/70R18 is 33.71" tall and 11.22" wide, and fits a 18" rim. In flotation (inch) sizing that is roughly 33.7x11.2R18.
285/70R18 dimensions
| Measurement | Inches | Metric |
|---|---|---|
| Overall diameter (height) | 33.71" | 856 mm |
| Section width | 11.22" | 285 mm |
| Sidewall height | 7.85" | 199.5 mm |
| Rim diameter | 18" | 457.2 mm |
| Circumference | 105.9" | 2690 mm |
| Revolutions per mile | 598 | |
| Aspect ratio | 70% (sidewall is 70% of the width) | |
Drawn to scale
Among the 122 sizes for 18" wheels on this site, 285/70R18 is #91 by height (shortest: 245/35R18, tallest: 340/80R18).
What people compare 285/70R18 with
Real comparisons drivers search for, worked out against 285/70R18:
| Compared size | Height | Width | Sidewall | Speedo at true 60 |
|---|---|---|---|---|
| 275/70R18 | -0.55" (-1.63%) | -0.39" | -0.27" | 61 mph |
| 295/70R18 | +0.55" (+1.63%) | +0.39" | +0.28" | 59 mph |
| 285/75R18 | +1.12" (+3.32%) | 0.00" | +0.57" | 58.1 mph |
| 285/65R18 | -1.12" (-3.32%) | 0.00" | -0.56" | 62.1 mph |
| 275/65R18 | -1.64" (-4.87%) | -0.39" | -0.81" | 63.1 mph |
| 265/70R18 | -1.10" (-3.26%) | -0.79" | -0.55" | 62 mph |
| 285/70R17 | -1.00" (-2.97%) | 0.00" | 0.00" | 61.8 mph |
How the 285/70R18 numbers are worked out
The size code reads as 285 mm section width, 70% aspect ratio, R for radial construction and 18-inch wheel.
- Sidewall = 285 × 70% = 199.5 mm = 7.85"
- Diameter = 18" + 2 × 7.85" = 33.71"
- Circumference = π × 33.71" = 105.9"
- Revs per mile = 63,360" ÷ 105.9" = 598
Sizes that can replace 285/70R18 on a 18" wheel
Within 3% of 33.71". Last column: speedometer reading at a true 60 mph.
| Size | Diameter | Width | Difference | Speedo at true 60 mph |
|---|---|---|---|---|
| 265/75R18 | 33.65" | 10.43" | -0.18% | 60.1 mph |
| 305/65R18 | 33.61" | 12.01" | -0.3% | 60.2 mph |
| 270/75R18 | 33.94" | 10.63" | +0.68% | 59.6 mph |
| 290/70R18 | 33.98" | 11.42" | +0.8% | 59.5 mph |
| 280/70R18 | 33.43" | 11.02" | -0.83% | 60.5 mph |
| 255/80R18 | 34.06" | 10.04" | +1.04% | 59.4 mph |
| 325/60R18 | 33.35" | 12.80" | -1.07% | 60.6 mph |
| 315/65R18 | 34.12" | 12.40" | +1.22% | 59.3 mph |
| 275/75R18 | 34.24" | 10.83" | +1.57% | 59.1 mph |
| 275/70R18 | 33.16" | 10.83" | -1.63% | 61 mph |
| 295/70R18 | 34.26" | 11.61" | +1.63% | 59 mph |
| 295/65R18 | 33.10" | 11.61" | -1.81% | 61.1 mph |
One size wider or narrower
Same height on a different wheel size
- 315/75R15 15" (-0.33%)
- 325/75R15 15" (+1.42%)
- 265/85R16 16" (+0.09%)
- 325/70R16 16" (+0.59%)
- 285/80R16 16" (+0.71%)
- 295/75R16 16" (-0.86%)
- 305/75R16 16" (+0.89%)
- 315/70R16 16" (-1.04%)
- 275/80R16 16" (-1.16%)
- 255/85R16 16" (-1.9%)
Questions about 285/70R18
How tall is a 285/70R18 tire in inches?
A 285/70R18 tire is 33.71 inches (856 mm) tall: the 18-inch rim plus two sidewalls of 7.85 inches each.
Is 285/70R18 a 34 inch tire?
Yes. At 33.71 inches tall it is commonly called a 34-inch tire.
How many revolutions per mile does a 285/70R18 make?
About 598 revolutions per mile, based on a calculated circumference of 105.9 inches.
What size can replace 285/70R18?
265/75R18 is the closest match on a 18" rim (-0.18% height). Check load index, speed rating and clearance first.
Compare 285/70R18 against any other size with the tire size calculator.