355/65R18 tire size
355/65R18 is a metric size: 36.2" tall, 14.0" wide, on a 18" rim — about a 36x14.00R18. The sidewall is 9.1" and the tire turns 558 times per mile.
355/65R18 specs
| Overall diameter (height) | 36.17" · 919 mm |
|---|---|
| Section width | 13.98" · 355 mm |
| Sidewall height | 9.08" · 231 mm (65% of width) |
| Rim diameter | 18" |
| Circumference | 113.63" · 2.886 m |
| Revolutions per mile | 558 (346 per km) |
| Inch (flotation) equivalent | 36x14.00R18 |
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 | |
|---|---|---|---|---|---|
| 35x12.50R18 common | 35.00" | -3.23% | -37 mm | 58.1 mph | calculate → |
| 285/75R18 | 34.83" | -3.70% | -70 mm | 57.8 mph | calculate → |
| 325/65R18 | 34.63" | -4.25% | -30 mm | 57.5 mph | calculate → |
| 305/70R18 | 34.81" | -3.76% | -50 mm | 57.7 mph | calculate → |
| 37x13.50R18 | 37.00" | +2.30% | -12 mm | 61.4 mph | calculate → |
| 37x12.50R18 | 37.00" | +2.30% | -37 mm | 61.4 mph | calculate → |
| 35x11.50R18 | 35.00" | -3.23% | -63 mm | 58.1 mph | calculate → |
| 315/70R18 | 35.36" | -2.23% | -40 mm | 58.7 mph | calculate → |
| 36x13.50R18 | 36.00" | -0.47% | -12 mm | 59.7 mph | calculate → |
| 37x11.50R18 | 37.00" | +2.30% | -63 mm | 61.4 mph | calculate → |
| 35x13.00R18 | 35.00" | -3.23% | -25 mm | 58.1 mph | calculate → |
| 35x14.50R18 | 35.00" | -3.23% | +13 mm | 58.1 mph | calculate → |
| 37x14.50R18 | 37.00" | +2.30% | +13 mm | 61.4 mph | calculate → |
| 35x13.50R18 | 35.00" | -3.23% | -12 mm | 58.1 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 | |
|---|---|---|---|---|---|
| 36x13.50R17 | 36.00" | -0.47% | -12 mm | 59.7 mph | calculate → |
| 36x12.50R17 | 36.00" | -0.47% | -37 mm | 59.7 mph | calculate → |
Try another size against 355/65R18
Questions
What size is 355/65R18 in inches?
355/65R18 is about 36.2" tall and 14.0" wide on a 18-inch rim — roughly a 36x14.00R18 in inch sizing.
What does 355/65R18 mean?
355 mm section width, sidewall 65% of the width (9.08"), radial construction, 18-inch rim.
What tire sizes are equivalent to 355/65R18?
On the same 18" rim, within 3% of the diameter: 36x13.50R18 (-0.47%), 315/70R18 (-2.23%), 37x11.50R18 (+2.30%), 37x12.50R18 (+2.30%), 37x13.50R18 (+2.30%), 37x14.50R18 (+2.30%).
How many revolutions per mile does a 355/65R18 tire make?
About 558 revolutions per mile (circumference 113.6").
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.