33x12.50R18 tire size
33x12.50R18 is a flotation (inch) size: 33.0" tall, 12.5" wide, on a 18" rim — about a 320/60R18. The sidewall is 7.5" and the tire turns 611 times per mile.
33x12.50R18 specs
| Overall diameter (height) | 33.00" · 838 mm |
|---|---|
| Section width | 12.50" · 318 mm |
| Sidewall height | 7.50" · 191 mm (60% of width) |
| Rim diameter | 18" |
| Circumference | 103.67" · 2.633 m |
| Revolutions per mile | 611 (380 per km) |
| Closest metric size | 320/60R18 |
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" | -2.80% | -43 mm | 58.3 mph | compare → |
| 275/70R18 common | 33.16" | +0.48% | -43 mm | 60.3 mph | compare → |
| 265/65R18 common | 31.56" | -4.35% | -53 mm | 57.4 mph | compare → |
| 265/70R18 common | 32.61" | -1.19% | -53 mm | 59.3 mph | compare → |
| 255/70R18 common | 32.06" | -2.86% | -63 mm | 58.3 mph | compare → |
| 285/65R18 common | 32.59" | -1.25% | -33 mm | 59.2 mph | compare → |
| 295/70R18 common | 34.26" | +3.82% | -23 mm | 62.3 mph | compare → |
| 285/60R18 | 31.46" | -4.65% | -33 mm | 57.2 mph | compare → |
| 325/65R18 | 34.63" | +4.95% | +7 mm | 63.0 mph | compare → |
| 305/65R18 | 33.61" | +1.85% | -13 mm | 61.1 mph | compare → |
| 305/60R18 | 32.41" | -1.79% | -13 mm | 58.9 mph | compare → |
| 285/70R18 | 33.71" | +2.15% | -33 mm | 61.3 mph | compare → |
| 325/60R18 | 33.35" | +1.07% | +7 mm | 60.6 mph | compare → |
| 245/75R18 | 32.47" | -1.61% | -73 mm | 59.0 mph | calculate → |
| 295/65R18 | 33.10" | +0.30% | -23 mm | 60.2 mph | calculate → |
| 245/70R18 | 31.50" | -4.53% | -73 mm | 57.3 mph | calculate → |
| 33x11.50R18 | 33.00" | 0.00% | -26 mm | 60.0 mph | calculate → |
| 33x13.50R18 | 33.00" | 0.00% | +25 mm | 60.0 mph | calculate → |
| 33x13.00R18 | 33.00" | 0.00% | +12 mm | 60.0 mph | calculate → |
| 235/80R18 | 32.80" | -0.60% | -83 mm | 59.6 mph | calculate → |
| 34x12.50R18 | 34.00" | +3.03% | 0 mm | 61.8 mph | calculate → |
| 33x10.50R18 | 33.00" | 0.00% | -51 mm | 60.0 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 | |
|---|---|---|---|---|---|
| 285/70R17 common | 32.71" | -0.88% | -33 mm | 59.5 mph | compare → |
| 295/70R17 | 33.26" | +0.79% | -23 mm | 60.5 mph | compare → |
| 33x12.50R17 | 33.00" | 0.00% | 0 mm | 60.0 mph | compare → |
| 255/80R17 | 33.06" | +0.19% | -63 mm | 60.1 mph | compare → |
| 33x10.50R17 | 33.00" | 0.00% | -51 mm | 60.0 mph | calculate → |
| 33x11.50R17 | 33.00" | 0.00% | -26 mm | 60.0 mph | calculate → |
| 33x13.50R17 | 33.00" | 0.00% | +25 mm | 60.0 mph | calculate → |
| 33x13.00R17 | 33.00" | 0.00% | +12 mm | 60.0 mph | calculate → |
| 33x9.50R17 | 33.00" | 0.00% | -77 mm | 60.0 mph | calculate → |
| 235/85R17 | 32.73" | -0.82% | -83 mm | 59.5 mph | calculate → |
Try another size against 33x12.50R18
Questions
What size is 33x12.50R18 in inches?
33x12.50R18 is about 33.0" tall and 12.5" wide on a 18-inch rim — roughly a 320/60R18 in inch sizing.
What does 33x12.50R18 mean?
33" overall diameter, 12.50" section width, radial, 18" rim.
What tire sizes are equivalent to 33x12.50R18?
On the same 18" rim, within 3% of the diameter: 33x10.50R18 (0.00%), 33x11.50R18 (0.00%), 33x13.50R18 (0.00%), 33x13.00R18 (0.00%), 295/65R18 (+0.30%), 275/70R18 (+0.48%).
How many revolutions per mile does a 33x12.50R18 tire make?
About 611 revolutions per mile (circumference 103.7").
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.