TireSizeCheck

275/70R18

A 275/70R18 tire is 33.16 inches tall and 10.8 inches wide, with a 7.58-inch sidewall, mounted on a 18-inch wheel.

Overall diameter

33.16″

842 mm

Sidewall height

7.58″

192.5 mm

Tread width

275 mm

10.8″

Circumference

104.17″

8.7 ft

Revs per mile

608

378 per km

Wheel diameter

18″

aspect ratio 70%

Cross-section

Overall diameter
33.16″
Sidewall (each side)
7.58″
Wheel
18″

275/70R18 in inches and millimeters

Every dimension of a 275/70R18, converted both ways. Calculated from the size code, accurate to about 1%.

Measurement Inches Millimeters
Overall diameter (height) 33.16″ 842 mm
Tread width 10.8″ 275 mm
Sidewall height 7.58″ 192.5 mm
Wheel diameter 18″ 457 mm
Circumference 104.17″ 2646 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.

275/70R18 compared with other sizes

All 33 practical swaps involving 275/70R18 — diameter change, speedometer impact and a fit verdict for each.

275/70R18 → 285/75R16

285/75R16

Diameter +1.0% · This fits

275/70R18 → 285/70R17

285/70R17

Diameter +1.4% · This fits

275/70R18 → 305/65R17

305/65R17

Diameter +1.7% · This fits

275/70R18 → 305/70R17

305/70R17

Diameter −1.9% · This fits

275/70R18 → 315/70R17

315/70R17

Diameter −3.5% · Borderline. Check clearance first

275/70R18 → 255/70R18

255/70R18

Diameter +3.4% · Borderline. Check clearance first

275/70R18 → 265/70R18

265/70R18

Diameter +1.7% · This fits

275/70R18 → 275/65R18

275/65R18

Diameter +3.4% · Borderline. Check clearance first

265/70R18 → 275/70R18

265/70R18

Diameter −1.7% · This fits

285/70R18 → 275/70R18

285/70R18

Diameter +1.7% · This fits

285/65R18 → 275/70R18

285/65R18

Diameter −1.7% · This fits

275/65R18 → 275/70R18

275/65R18

Diameter −3.3% · Borderline. Check clearance first

305/60R18 → 275/70R18

305/60R18

Diameter −2.3% · This fits

255/70R18 → 275/70R18

255/70R18

Diameter −3.3% · Borderline. Check clearance first

295/70R18 → 275/70R18

295/70R18

Diameter +3.3% · Borderline. Check clearance first

275/60R20 → 275/70R18

275/60R20

Diameter −0.5% · This fits

265/65R18 → 275/70R18

265/65R18

Diameter −4.8% · Borderline. Check clearance first

285/60R18 → 275/70R18

285/60R18

Diameter −5.1% · Too big a jump

305/55R20 → 275/70R18

305/55R20

Diameter +0.2% · This fits

285/60R20 → 275/70R18

285/60R20

Diameter +0.9% · This fits

285/75R16 → 275/70R18

285/75R16

Diameter −1.0% · This fits

285/70R17 → 275/70R18

285/70R17

Diameter −1.4% · This fits

275/70R18 → 285/65R18

285/65R18

Diameter +1.8% · This fits

275/70R18 → 285/70R18

285/70R18

Diameter −1.6% · This fits

275/70R18 → 295/70R18

295/70R18

Diameter −3.2% · Borderline. Check clearance first

275/70R18 → 305/60R18

305/60R18

Diameter +2.3% · This fits

275/70R18 → 275/60R20

275/60R20

Diameter +0.5% · This fits

275/70R18 → 275/65R20

275/65R20

Diameter −2.7% · This fits

275/70R18 → 285/60R20

285/60R20

Diameter −0.9% · This fits

275/70R18 → 285/65R20

285/65R20

Diameter −4.1% · Borderline. Check clearance first

275/70R18 → 295/60R20

295/60R20

Diameter −2.3% · This fits

275/70R18 → 305/55R20

305/55R20

Diameter −0.2% · This fits

275/70R18 → 235/45R18

235/45R18

Diameter +25.9% · Too big a jump

Common questions

What is 275/70R18 in inches?
A 275/70R18 tire is 33.16 inches tall and 10.8 inches wide, with a 7.58-inch sidewall, mounted on a 18-inch wheel. In metric that is 842 mm tall and 275 mm wide. The circumference is 104.17 inches.
How tall is a 275/70R18 tire?
33.16 inches, or 842 mm. That is the overall diameter, wheel included. It turns about 608 times per mile, which is what your speedometer counts.
What do the numbers in 275/70R18 mean?
275 is the tread width in millimeters, 70 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 275 × 70% = 192.5 mm tall.