235/65R18
A 235/65R18 tire is 30.03 inches tall and 9.3 inches wide, with a 6.01-inch sidewall, mounted on a 18-inch wheel.
Overall diameter
30.03″
763 mm
Sidewall height
6.01″
152.8 mm
Tread width
235 mm
9.3″
Circumference
94.33″
7.9 ft
Revs per mile
672
417 per km
Wheel diameter
18″
aspect ratio 65%
Cross-section
- Overall diameter
- 30.03″
- Sidewall (each side)
- 6.01″
- Wheel
- 18″
235/65R18 in inches and millimeters
Every dimension of a 235/65R18, converted both ways. Calculated from the size code, accurate to about 1%.
| Measurement | Inches | Millimeters |
|---|---|---|
| Overall diameter (height) | 30.03″ | 763 mm |
| Tread width | 9.3″ | 235 mm |
| Sidewall height | 6.01″ | 152.8 mm |
| Wheel diameter | 18″ | 457 mm |
| Circumference | 94.33″ | 2396 mm |
Nominal dimensions from the size code. A real tire varies by a few millimeters between manufacturers, and a loaded tire sits slightly shorter than its free diameter.
235/65R18 compared with other sizes
All 30 practical swaps involving 235/65R18 — diameter change, speedometer impact and a fit verdict for each.
235/65R18 → 245/75R16
245/75R16
Diameter −1.4% · This fits
235/65R18 → 235/60R18
235/60R18
Diameter +3.2% · Borderline. Check clearance first
235/65R18 → 255/55R18
255/55R18
Diameter +3.4% · Borderline. Check clearance first
235/65R18 → 265/60R18
265/60R18
Diameter −1.6% · This fits
235/65R18 → 275/45R20
275/45R20
Diameter +1.0% · This fits
235/65R18 → 245/70R16
245/70R16
Diameter +1.8% · This fits
235/65R18 → 255/70R16
255/70R16
Diameter −0.1% · This fits
235/65R18 → 255/65R17
255/65R17
Diameter −0.1% · This fits
235/65R18 → 225/60R18
225/60R18
Diameter +4.9% · Borderline. Check clearance first
255/60R18 → 235/65R18
255/60R18
Diameter +0.1% · This fits
245/60R18 → 235/65R18
245/60R18
Diameter −1.5% · This fits
265/60R18 → 235/65R18
265/60R18
Diameter +1.6% · This fits
245/65R18 → 235/65R18
245/65R18
Diameter +1.7% · This fits
235/60R18 → 235/65R18
235/60R18
Diameter −3.1% · Borderline. Check clearance first
275/60R18 → 235/65R18
275/60R18
Diameter +3.2% · Borderline. Check clearance first
255/55R18 → 235/65R18
255/55R18
Diameter −3.3% · Borderline. Check clearance first
255/65R18 → 235/65R18
255/65R18
Diameter +3.4% · Borderline. Check clearance first
225/60R18 → 235/65R18
225/60R18
Diameter −4.7% · Borderline. Check clearance first
255/50R20 → 235/65R18
255/50R20
Diameter +0.0% · This fits
255/65R17 → 235/65R18
255/65R17
Diameter +0.1% · This fits
255/70R16 → 235/65R18
255/70R16
Diameter +0.1% · This fits
265/65R18 → 235/65R18
265/65R18
Diameter +5.1% · Too big a jump
275/45R20 → 235/65R18
275/45R20
Diameter −0.9% · This fits
235/65R18 → 245/60R18
245/60R18
Diameter +1.5% · This fits
235/65R18 → 245/65R18
245/65R18
Diameter −1.7% · This fits
235/65R18 → 255/60R18
255/60R18
Diameter −0.1% · This fits
235/65R18 → 255/65R18
255/65R18
Diameter −3.3% · Borderline. Check clearance first
235/65R18 → 275/60R18
275/60R18
Diameter −3.1% · Borderline. Check clearance first
235/65R18 → 255/50R20
255/50R20
Diameter −0.0% · This fits
235/65R18 → 235/45R18
235/45R18
Diameter +14.1% · Too big a jump
Common questions
- What is 235/65R18 in inches?
- A 235/65R18 tire is 30.03 inches tall and 9.3 inches wide, with a 6.01-inch sidewall, mounted on a 18-inch wheel. In metric that is 763 mm tall and 235 mm wide. The circumference is 94.33 inches.
- How tall is a 235/65R18 tire?
- 30.03 inches, or 763 mm. That is the overall diameter, wheel included. It turns about 672 times per mile, which is what your speedometer counts.
- What do the numbers in 235/65R18 mean?
- 235 is the tread width in millimeters, 65 is the aspect ratio — the sidewall height as a percentage of the tread width — and 18 is the wheel diameter in inches. So the sidewall is 235 × 65% = 152.8 mm tall.