305/60R18
A 305/60R18 tire is 32.41 inches tall and 12.0 inches wide, with a 7.20-inch sidewall, mounted on a 18-inch wheel.
Overall diameter
32.41″
823 mm
Sidewall height
7.20″
183.0 mm
Tread width
305 mm
12.0″
Circumference
101.82″
8.5 ft
Revs per mile
622
387 per km
Wheel diameter
18″
aspect ratio 60%
Cross-section
- Overall diameter
- 32.41″
- Sidewall (each side)
- 7.20″
- Wheel
- 18″
305/60R18 in inches and millimeters
Every dimension of a 305/60R18, converted both ways. Calculated from the size code, accurate to about 1%.
| Measurement | Inches | Millimeters |
|---|---|---|
| Overall diameter (height) | 32.41″ | 823 mm |
| Tread width | 12.0″ | 305 mm |
| Sidewall height | 7.20″ | 183.0 mm |
| Wheel diameter | 18″ | 457 mm |
| Circumference | 101.82″ | 2586 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.
305/60R18 compared with other sizes
All 32 practical swaps involving 305/60R18 — diameter change, speedometer impact and a fit verdict for each.
305/60R18 → 285/75R16
285/75R16
Diameter −1.3% · This fits
305/60R18 → 275/70R17
275/70R17
Diameter +0.8% · This fits
305/60R18 → 285/70R17
285/70R17
Diameter −0.9% · This fits
305/60R18 → 305/65R17
305/65R17
Diameter −0.6% · This fits
305/60R18 → 305/70R17
305/70R17
Diameter −4.1% · Borderline. Check clearance first
305/60R18 → 265/65R18
265/65R18
Diameter +2.7% · This fits
305/60R18 → 265/70R18
265/70R18
Diameter −0.6% · This fits
305/60R18 → 275/60R18
275/60R18
Diameter +4.6% · Borderline. Check clearance first
305/60R18 → 275/65R18
275/65R18
Diameter +1.0% · This fits
305/60R18 → 275/70R18
275/70R18
Diameter −2.3% · This fits
305/60R18 → 285/60R18
285/60R18
Diameter +3.0% · Borderline. Check clearance first
305/60R18 → 285/65R18
285/65R18
Diameter −0.5% · This fits
305/60R18 → 285/70R18
285/70R18
Diameter −3.9% · Borderline. Check clearance first
305/60R18 → 295/70R18
295/70R18
Diameter −5.4% · Too big a jump
285/65R18 → 305/60R18
285/65R18
Diameter +0.5% · This fits
265/70R18 → 305/60R18
265/70R18
Diameter +0.6% · This fits
275/65R18 → 305/60R18
275/65R18
Diameter −1.0% · This fits
275/70R18 → 305/60R18
275/70R18
Diameter +2.3% · This fits
265/65R18 → 305/60R18
265/65R18
Diameter −2.6% · This fits
285/60R18 → 305/60R18
285/60R18
Diameter −2.9% · This fits
285/70R18 → 305/60R18
285/70R18
Diameter +4.0% · Borderline. Check clearance first
305/65R17 → 305/60R18
305/65R17
Diameter +0.6% · This fits
275/60R18 → 305/60R18
275/60R18
Diameter −4.4% · Borderline. Check clearance first
305/50R20 → 305/60R18
305/50R20
Diameter −1.2% · This fits
285/55R20 → 305/60R18
285/55R20
Diameter −0.2% · This fits
265/60R20 → 305/60R18
265/60R20
Diameter +0.3% · This fits
275/70R17 → 305/60R18
275/70R17
Diameter −0.8% · This fits
285/70R17 → 305/60R18
285/70R17
Diameter +0.9% · This fits
305/60R18 → 265/60R20
265/60R20
Diameter −0.3% · This fits
305/60R18 → 285/55R20
285/55R20
Diameter +0.2% · This fits
305/60R18 → 305/50R20
305/50R20
Diameter +1.3% · This fits
305/60R18 → 235/45R18
235/45R18
Diameter +23.1% · Too big a jump
Common questions
- What is 305/60R18 in inches?
- A 305/60R18 tire is 32.41 inches tall and 12.0 inches wide, with a 7.20-inch sidewall, mounted on a 18-inch wheel. In metric that is 823 mm tall and 305 mm wide. The circumference is 101.82 inches.
- How tall is a 305/60R18 tire?
- 32.41 inches, or 823 mm. That is the overall diameter, wheel included. It turns about 622 times per mile, which is what your speedometer counts.
- What do the numbers in 305/60R18 mean?
- 305 is the tread width in millimeters, 60 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 305 × 60% = 183.0 mm tall.