34x12.50R18 tire size
34x12.50R18 is a flotation (inch) size: 34.0" tall, 12.5" wide, on a 18" rim — about a 320/65R18. The sidewall is 8.0" and the tire turns 593 times per mile.
34x12.50R18 specs
| Overall diameter (height) | 34.00" · 864 mm |
|---|---|
| Section width | 12.50" · 318 mm |
| Sidewall height | 8.00" · 203 mm (64% of width) |
| Rim diameter | 18" |
| Circumference | 106.81" · 2.713 m |
| Revolutions per mile | 593 (369 per km) |
| Closest metric size | 320/65R18 |
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 | |
|---|---|---|---|---|---|
| 275/70R18 common | 33.16" | -2.48% | -43 mm | 58.5 mph | calculate → |
| 265/70R18 common | 32.61" | -4.10% | -53 mm | 57.5 mph | calculate → |
| 35x12.50R18 common | 35.00" | +2.94% | 0 mm | 61.8 mph | calculate → |
| 285/65R18 common | 32.59" | -4.16% | -33 mm | 57.5 mph | calculate → |
| 295/70R18 common | 34.26" | +0.76% | -23 mm | 60.5 mph | calculate → |
| 33x12.50R18 | 33.00" | -2.94% | 0 mm | 58.2 mph | calculate → |
| 285/75R18 | 34.83" | +2.44% | -33 mm | 61.5 mph | calculate → |
| 325/65R18 | 34.63" | +1.86% | +7 mm | 61.1 mph | calculate → |
| 305/70R18 | 34.81" | +2.39% | -13 mm | 61.4 mph | calculate → |
| 305/65R18 | 33.61" | -1.15% | -13 mm | 59.3 mph | calculate → |
| 285/70R18 | 33.71" | -0.86% | -33 mm | 59.5 mph | calculate → |
| 305/60R18 | 32.41" | -4.68% | -13 mm | 57.2 mph | calculate → |
| 325/60R18 | 33.35" | -1.90% | +7 mm | 58.9 mph | calculate → |
| 245/75R18 | 32.47" | -4.50% | -73 mm | 57.3 mph | calculate → |
| 295/65R18 | 33.10" | -2.65% | -23 mm | 58.4 mph | calculate → |
| 35x11.50R18 | 35.00" | +2.94% | -26 mm | 61.8 mph | calculate → |
| 315/70R18 | 35.36" | +4.01% | -3 mm | 62.4 mph | calculate → |
| 33x11.50R18 | 33.00" | -2.94% | -26 mm | 58.2 mph | calculate → |
| 33x13.50R18 | 33.00" | -2.94% | +25 mm | 58.2 mph | calculate → |
| 33x13.00R18 | 33.00" | -2.94% | +12 mm | 58.2 mph | calculate → |
| 35x13.00R18 | 35.00" | +2.94% | +12 mm | 61.8 mph | calculate → |
| 35x14.50R18 | 35.00" | +2.94% | +50 mm | 61.8 mph | calculate → |
| 235/80R18 | 32.80" | -3.52% | -83 mm | 57.9 mph | calculate → |
| 33x10.50R18 | 33.00" | -2.94% | -51 mm | 58.2 mph | calculate → |
| 35x13.50R18 | 35.00" | +2.94% | +25 mm | 61.8 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" | -0.50% | -33 mm | 59.7 mph | calculate → |
| 305/70R17 | 33.81" | -0.56% | -13 mm | 59.7 mph | calculate → |
| 34x10.50R17 | 34.00" | 0.00% | -51 mm | 60.0 mph | calculate → |
| 255/85R17 | 34.07" | +0.20% | -63 mm | 60.1 mph | calculate → |
| 275/80R17 | 34.32" | +0.95% | -43 mm | 60.6 mph | calculate → |
Try another size against 34x12.50R18
Questions
What size is 34x12.50R18 in inches?
34x12.50R18 is about 34.0" tall and 12.5" wide on a 18-inch rim — roughly a 320/65R18 in inch sizing.
What does 34x12.50R18 mean?
34" overall diameter, 12.50" section width, radial, 18" rim.
What tire sizes are equivalent to 34x12.50R18?
On the same 18" rim, within 3% of the diameter: 295/70R18 (+0.76%), 285/70R18 (-0.86%), 305/65R18 (-1.15%), 325/65R18 (+1.86%), 325/60R18 (-1.90%), 305/70R18 (+2.39%).
How many revolutions per mile does a 34x12.50R18 tire make?
About 593 revolutions per mile (circumference 106.8").
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.