285/70R18 tire size
285/70R18 is a metric size: 33.7" tall, 11.2" wide, on a 18" rim — about a 33.5x11.00R18. The sidewall is 7.9" and the tire turns 598 times per mile.
285/70R18 specs
| Overall diameter (height) | 33.71" · 856 mm |
|---|---|
| Section width | 11.22" · 285 mm |
| Sidewall height | 7.85" · 200 mm (70% of width) |
| Rim diameter | 18" |
| Circumference | 105.90" · 2.690 m |
| Revolutions per mile | 598 (372 per km) |
| Inch (flotation) equivalent | 33.5x11.00R18 |
Equivalent sizes on a 18" rim
Sizes within ±5% of the overall diameter. Green rows are inside the usual ±3% limit for keeping the speedometer, ABS and gearing right; red rows are bigger changes that need clearance checks.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 275/65R18 common | 32.07" | -4.85% | -10 mm | 57.1 mph | compare → |
| 275/70R18 common | 33.16" | -1.64% | -10 mm | 59.0 mph | compare → |
| 265/70R18 common | 32.61" | -3.27% | -20 mm | 58.0 mph | compare → |
| 255/70R18 common | 32.06" | -4.91% | -30 mm | 57.1 mph | compare → |
| 35x12.50R18 common | 35.00" | +3.83% | +33 mm | 62.3 mph | compare → |
| 285/65R18 common | 32.59" | -3.33% | 0 mm | 58.0 mph | compare → |
| 295/70R18 common | 34.26" | +1.64% | +10 mm | 61.0 mph | compare → |
| 33x12.50R18 | 33.00" | -2.10% | +33 mm | 58.7 mph | compare → |
| 285/75R18 | 34.83" | +3.33% | 0 mm | 62.0 mph | compare → |
| 325/65R18 | 34.63" | +2.74% | +40 mm | 61.6 mph | compare → |
| 305/70R18 | 34.81" | +3.27% | +20 mm | 62.0 mph | compare → |
| 305/65R18 | 33.61" | -0.29% | +20 mm | 59.8 mph | compare → |
| 305/60R18 | 32.41" | -3.85% | +20 mm | 57.7 mph | compare → |
| 325/60R18 | 33.35" | -1.05% | +40 mm | 59.4 mph | compare → |
| 245/75R18 | 32.47" | -3.68% | -40 mm | 57.8 mph | calculate → |
| 295/65R18 | 33.10" | -1.81% | +10 mm | 58.9 mph | calculate → |
| 35x11.50R18 | 35.00" | +3.83% | +7 mm | 62.3 mph | calculate → |
| 315/70R18 | 35.36" | +4.91% | +30 mm | 62.9 mph | calculate → |
| 34x12.50R18 | 34.00" | +0.86% | +33 mm | 60.5 mph | calculate → |
| 33x11.50R18 | 33.00" | -2.10% | +7 mm | 58.7 mph | calculate → |
| 33x13.50R18 | 33.00" | -2.10% | +58 mm | 58.7 mph | calculate → |
| 33x13.00R18 | 33.00" | -2.10% | +45 mm | 58.7 mph | calculate → |
| 235/80R18 | 32.80" | -2.69% | -50 mm | 58.4 mph | calculate → |
| 35x13.00R18 | 35.00" | +3.83% | +45 mm | 62.3 mph | calculate → |
| 35x14.50R18 | 35.00" | +3.83% | +83 mm | 62.3 mph | calculate → |
| 33x10.50R18 | 33.00" | -2.10% | -18 mm | 58.7 mph | calculate → |
| 35x13.50R18 | 35.00" | +3.83% | +58 mm | 62.3 mph | calculate → |
Plus / minus sizing: 17" and 19" rims
Same overall height on a different rim. Check wheel width and clearance before switching.
| Size | Diameter | Difference | Width | Speedo at 60 | |
|---|---|---|---|---|---|
| 285/75R17 | 33.83" | +0.36% | 0 mm | 60.2 mph | compare → |
| 305/70R17 | 33.81" | +0.30% | +20 mm | 60.2 mph | compare → |
| 34x10.50R17 | 34.00" | +0.86% | -18 mm | 60.5 mph | calculate → |
Try another size against 285/70R18
Questions
What size is 285/70R18 in inches?
285/70R18 is about 33.7" tall and 11.2" wide on a 18-inch rim — roughly a 33.5x11.00R18 in inch sizing.
What does 285/70R18 mean?
285 mm section width, sidewall 70% of the width (7.85"), radial construction, 18-inch rim.
What tire sizes are equivalent to 285/70R18?
On the same 18" rim, within 3% of the diameter: 305/65R18 (-0.29%), 34x12.50R18 (+0.86%), 325/60R18 (-1.05%), 295/70R18 (+1.64%), 275/70R18 (-1.64%), 295/65R18 (-1.81%).
How many revolutions per mile does a 285/70R18 tire make?
About 598 revolutions per mile (circumference 105.9").
How these numbers are computed
Diameter = rim + 2 × sidewall, sidewall = width × aspect ÷ 100, circumference = π × diameter, revolutions per mile = 63,360 ÷ circumference. Real tires differ by brand by a few tenths of an inch. Last reviewed October 14, 2026.