325/65R18 tire size
325/65R18 is a metric size: 34.6" tall, 12.8" wide, on a 18" rim — about a 34.5x13.00R18. The sidewall is 8.3" and the tire turns 582 times per mile.
325/65R18 specs
| Overall diameter (height) | 34.63" · 880 mm |
|---|---|
| Section width | 12.80" · 325 mm |
| Sidewall height | 8.32" · 211 mm (65% of width) |
| Rim diameter | 18" |
| Circumference | 108.81" · 2.764 m |
| Revolutions per mile | 582 (362 per km) |
| Inch (flotation) equivalent | 34.5x13.00R18 |
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 | |
|---|---|---|---|---|---|
| 275/70R18 common | 33.16" | -4.26% | -50 mm | 57.4 mph | compare → |
| 35x12.50R18 common | 35.00" | +1.06% | -7 mm | 60.6 mph | compare → |
| 295/70R18 common | 34.26" | -1.08% | -30 mm | 59.4 mph | compare → |
| 33x12.50R18 | 33.00" | -4.72% | -7 mm | 57.2 mph | compare → |
| 285/75R18 | 34.83" | +0.57% | -40 mm | 60.3 mph | compare → |
| 305/70R18 | 34.81" | +0.51% | -20 mm | 60.3 mph | compare → |
| 305/65R18 | 33.61" | -2.96% | -20 mm | 58.2 mph | compare → |
| 285/70R18 | 33.71" | -2.67% | -40 mm | 58.4 mph | compare → |
| 325/60R18 | 33.35" | -3.69% | 0 mm | 57.8 mph | compare → |
| 35x11.50R18 | 35.00" | +1.06% | -33 mm | 60.6 mph | calculate → |
| 295/65R18 | 33.10" | -4.43% | -30 mm | 57.3 mph | calculate → |
| 315/70R18 | 35.36" | +2.10% | -10 mm | 61.3 mph | calculate → |
| 35x13.00R18 | 35.00" | +1.06% | +5 mm | 60.6 mph | calculate → |
| 35x14.50R18 | 35.00" | +1.06% | +43 mm | 60.6 mph | calculate → |
| 34x12.50R18 | 34.00" | -1.83% | -7 mm | 58.9 mph | calculate → |
| 36x13.50R18 | 36.00" | +3.94% | +18 mm | 62.4 mph | calculate → |
| 33x11.50R18 | 33.00" | -4.72% | -33 mm | 57.2 mph | calculate → |
| 33x13.50R18 | 33.00" | -4.72% | +18 mm | 57.2 mph | calculate → |
| 33x13.00R18 | 33.00" | -4.72% | +5 mm | 57.2 mph | calculate → |
| 35x13.50R18 | 35.00" | +1.06% | +18 mm | 60.6 mph | calculate → |
| 355/65R18 | 36.17" | +4.43% | +30 mm | 62.7 mph | calculate → |
| 33x10.50R18 | 33.00" | -4.72% | -58 mm | 57.2 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 | |
|---|---|---|---|---|---|
| 315/70R17 common | 34.36" | -0.78% | -10 mm | 59.5 mph | compare → |
| 275/80R17 | 34.32" | -0.90% | -50 mm | 59.5 mph | calculate → |
| 325/70R17 | 34.91" | +0.81% | 0 mm | 60.5 mph | calculate → |
Try another size against 325/65R18
Questions
What size is 325/65R18 in inches?
325/65R18 is about 34.6" tall and 12.8" wide on a 18-inch rim — roughly a 34.5x13.00R18 in inch sizing.
What does 325/65R18 mean?
325 mm section width, sidewall 65% of the width (8.32"), radial construction, 18-inch rim.
What tire sizes are equivalent to 325/65R18?
On the same 18" rim, within 3% of the diameter: 305/70R18 (+0.51%), 285/75R18 (+0.57%), 35x11.50R18 (+1.06%), 35x12.50R18 (+1.06%), 35x13.50R18 (+1.06%), 35x13.00R18 (+1.06%).
How many revolutions per mile does a 325/65R18 tire make?
About 582 revolutions per mile (circumference 108.8").
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.