TireSizeCheck

285/65R18

A 285/65R18 tire is 32.59 inches tall and 11.2 inches wide, with a 7.29-inch sidewall, mounted on a 18-inch wheel.

Overall diameter

32.59″

828 mm

Sidewall height

7.29″

185.3 mm

Tread width

285 mm

11.2″

Circumference

102.37″

8.5 ft

Revs per mile

619

385 per km

Wheel diameter

18″

aspect ratio 65%

Cross-section

Overall diameter
32.59″
Sidewall (each side)
7.29″
Wheel
18″

285/65R18 in inches and millimeters

Every dimension of a 285/65R18, converted both ways. Calculated from the size code, accurate to about 1%.

Measurement Inches Millimeters
Overall diameter (height) 32.59″ 828 mm
Tread width 11.2″ 285 mm
Sidewall height 7.29″ 185.3 mm
Wheel diameter 18″ 457 mm
Circumference 102.37″ 2600 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.

285/65R18 compared with other sizes

All 35 practical swaps involving 285/65R18 — diameter change, speedometer impact and a fit verdict for each.

285/65R18 → 285/75R16

285/75R16

Diameter −0.7% · This fits

285/65R18 → 255/75R17

255/75R17

Diameter +1.6% · This fits

285/65R18 → 285/70R17

285/70R17

Diameter −0.4% · This fits

285/65R18 → 305/65R17

305/65R17

Diameter −0.1% · This fits

285/65R18 → 305/70R17

305/70R17

Diameter −3.6% · Borderline. Check clearance first

285/65R18 → 315/70R17

315/70R17

Diameter −5.2% · Too big a jump

285/65R18 → 255/65R18

255/65R18

Diameter +4.9% · Borderline. Check clearance first

285/65R18 → 255/70R18

255/70R18

Diameter +1.7% · This fits

285/65R18 → 265/65R18

265/65R18

Diameter +3.2% · Borderline. Check clearance first

285/65R18 → 265/70R18

265/70R18

Diameter −0.1% · This fits

285/65R18 → 275/60R18

275/60R18

Diameter +5.1% · Too big a jump

285/65R18 → 275/65R18

275/65R18

Diameter +1.6% · This fits

285/65R18 → 275/70R18

275/70R18

Diameter −1.7% · This fits

285/65R18 → 285/60R18

285/60R18

Diameter +3.6% · Borderline. Check clearance first

265/70R18 → 285/65R18

265/70R18

Diameter +0.1% · This fits

305/60R18 → 285/65R18

305/60R18

Diameter −0.5% · This fits

275/65R18 → 285/65R18

275/65R18

Diameter −1.6% · This fits

255/70R18 → 285/65R18

255/70R18

Diameter −1.6% · This fits

275/70R18 → 285/65R18

275/70R18

Diameter +1.8% · This fits

285/60R18 → 285/65R18

285/60R18

Diameter −3.4% · Borderline. Check clearance first

285/70R18 → 285/65R18

285/70R18

Diameter +3.4% · Borderline. Check clearance first

265/65R18 → 285/65R18

265/65R18

Diameter −3.1% · Borderline. Check clearance first

285/70R17 → 285/65R18

285/70R17

Diameter +0.4% · This fits

285/75R16 → 285/65R18

285/75R16

Diameter +0.7% · This fits

285/55R20 → 285/65R18

285/55R20

Diameter −0.7% · This fits

255/65R18 → 285/65R18

255/65R18

Diameter −4.7% · Borderline. Check clearance first

275/60R18 → 285/65R18

275/60R18

Diameter −4.9% · Borderline. Check clearance first

305/65R17 → 285/65R18

305/65R17

Diameter +0.1% · This fits

285/65R18 → 285/70R18

285/70R18

Diameter −3.3% · Borderline. Check clearance first

285/65R18 → 295/70R18

295/70R18

Diameter −4.9% · Borderline. Check clearance first

285/65R18 → 305/60R18

305/60R18

Diameter +0.5% · This fits

285/65R18 → 265/60R20

265/60R20

Diameter +0.2% · This fits

285/65R18 → 285/55R20

285/55R20

Diameter +0.8% · This fits

285/65R18 → 285/60R20

285/60R20

Diameter −2.6% · This fits

285/65R18 → 235/45R18

235/45R18

Diameter +23.8% · Too big a jump

Common questions

What is 285/65R18 in inches?
A 285/65R18 tire is 32.59 inches tall and 11.2 inches wide, with a 7.29-inch sidewall, mounted on a 18-inch wheel. In metric that is 828 mm tall and 285 mm wide. The circumference is 102.37 inches.
How tall is a 285/65R18 tire?
32.59 inches, or 828 mm. That is the overall diameter, wheel included. It turns about 619 times per mile, which is what your speedometer counts.
What do the numbers in 285/65R18 mean?
285 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 285 × 65% = 185.3 mm tall.