Home › 18" tire sizes › 325/65R18
325/65R18 tire size in inches
325/65R18 is 34.63" tall and 12.80" wide, and fits a 18" rim. In flotation (inch) sizing that is roughly 34.6x12.8R18.
325/65R18 dimensions
| Measurement | Inches | Metric |
|---|---|---|
| Overall diameter (height) | 34.63" | 880 mm |
| Section width | 12.80" | 325 mm |
| Sidewall height | 8.32" | 211.2 mm |
| Rim diameter | 18" | 457.2 mm |
| Circumference | 108.8" | 2764 mm |
| Revolutions per mile | 582 | |
| Aspect ratio | 65% (sidewall is 65% of the width) | |
Drawn to scale
Among the 122 sizes for 18" wheels on this site, 325/65R18 is #99 by height (shortest: 245/35R18, tallest: 340/80R18).
What people compare 325/65R18 with
Real comparisons drivers search for, worked out against 325/65R18:
| Compared size | Height | Width | Sidewall | Speedo at true 60 |
|---|---|---|---|---|
| 275/70R18 | -1.47" (-4.24%) | -1.97" | -0.74" | 62.7 mph |
| 295/70R18 | -0.37" (-1.07%) | -1.19" | -0.19" | 60.6 mph |
325/65R18 against the most popular 18" sizes
| Popular size | Height | Width | Sidewall | Speedo at true 60 |
|---|---|---|---|---|
| 275/65R18 | -2.56" (-7.39%) | -1.97" | -1.28" | 64.8 mph |
| 285/65R18 | -2.04" (-5.89%) | -1.58" | -1.03" | 63.8 mph |
| 305/70R18 | +0.18" (+0.52%) | -0.79" | +0.09" | 59.7 mph |
| 285/70R18 | -0.92" (-2.66%) | -1.58" | -0.47" | 61.6 mph |
| 285/75R18 | +0.20" (+0.58%) | -1.58" | +0.10" | 59.7 mph |
How the 325/65R18 numbers are worked out
The size code reads as 325 mm section width, 65% aspect ratio, R for radial construction and 18-inch wheel.
- Sidewall = 325 × 65% = 211.2 mm = 8.32"
- Diameter = 18" + 2 × 8.32" = 34.63"
- Circumference = π × 34.63" = 108.8"
- Revs per mile = 63,360" ÷ 108.8" = 582
Sizes that can replace 325/65R18 on a 18" wheel
Within 3% of 34.63". Last column: speedometer reading at a true 60 mph.
| Size | Diameter | Width | Difference | Speedo at true 60 mph |
|---|---|---|---|---|
| 265/80R18 | 34.69" | 10.43" | +0.17% | 59.9 mph |
| 280/75R18 | 34.54" | 11.02" | -0.26% | 60.2 mph |
| 305/70R18 | 34.81" | 12.01" | +0.52% | 59.7 mph |
| 285/75R18 | 34.83" | 11.22" | +0.58% | 59.7 mph |
| 295/70R18 | 34.26" | 11.61" | -1.07% | 60.6 mph |
| 275/75R18 | 34.24" | 10.83" | -1.13% | 60.7 mph |
| 255/85R18 | 35.07" | 10.04" | +1.27% | 59.2 mph |
| 315/65R18 | 34.12" | 12.40" | -1.47% | 60.9 mph |
| 335/65R18 | 35.15" | 13.19" | +1.5% | 59.1 mph |
| 255/80R18 | 34.06" | 10.04" | -1.65% | 61 mph |
| 290/70R18 | 33.98" | 11.42" | -1.88% | 61.1 mph |
| 275/80R18 | 35.32" | 10.83" | +1.99% | 58.8 mph |
One size wider or narrower
- Narrower: 315/65R18 — 12.40" wide, 34.12" tall
- Wider: 335/65R18 — 13.19" wide, 35.15" tall
Same height on a different wheel size
- 325/75R15 15" (-1.27%)
- 315/75R16 16" (-0.09%)
- 295/80R16 16" (-0.14%)
- 275/85R16 16" (-0.64%)
- 285/85R16 16" (+1.27%)
- 325/75R16 16" (+1.62%)
- 375/65R16 16" (+1.62%)
- 305/80R16 16" (+1.67%)
- 305/75R16 16" (-1.79%)
- 285/80R16 16" (-1.96%)
Questions about 325/65R18
How tall is a 325/65R18 tire in inches?
A 325/65R18 tire is 34.63 inches (880 mm) tall: the 18-inch rim plus two sidewalls of 8.32 inches each.
Is 325/65R18 a 35 inch tire?
Yes. At 34.63 inches tall it is commonly called a 35-inch tire.
How many revolutions per mile does a 325/65R18 make?
About 582 revolutions per mile, based on a calculated circumference of 108.8 inches.
What size can replace 325/65R18?
265/80R18 is the closest match on a 18" rim (+0.17% height). Check load index, speed rating and clearance first.
Compare 325/65R18 against any other size with the tire size calculator.