TireSizeCheck

275/70R18

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 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% · Good fit

275/70R18 → 285/70R17

285/70R17

Diameter +1.4% · Good fit

275/70R18 → 305/65R17

305/65R17

Diameter +1.7% · Good fit

275/70R18 → 305/70R17

305/70R17

Diameter −1.9% · Good fit

275/70R18 → 315/70R17

315/70R17

Diameter −3.5% · Marginal fit — proceed with care

275/70R18 → 255/70R18

255/70R18

Diameter +3.4% · Marginal fit — proceed with care

275/70R18 → 265/70R18

265/70R18

Diameter +1.7% · Good fit

275/70R18 → 275/65R18

275/65R18

Diameter +3.4% · Marginal fit — proceed with care

265/70R18 → 275/70R18

265/70R18

Diameter −1.7% · Good fit

285/70R18 → 275/70R18

285/70R18

Diameter +1.7% · Good fit

285/65R18 → 275/70R18

285/65R18

Diameter −1.7% · Good fit

275/65R18 → 275/70R18

275/65R18

Diameter −3.3% · Marginal fit — proceed with care

305/60R18 → 275/70R18

305/60R18

Diameter −2.3% · Good fit

255/70R18 → 275/70R18

255/70R18

Diameter −3.3% · Marginal fit — proceed with care

295/70R18 → 275/70R18

295/70R18

Diameter +3.3% · Marginal fit — proceed with care

275/60R20 → 275/70R18

275/60R20

Diameter −0.5% · Good fit

265/65R18 → 275/70R18

265/65R18

Diameter −4.8% · Marginal fit — proceed with care

285/60R18 → 275/70R18

285/60R18

Diameter −5.1% · Not recommended

305/55R20 → 275/70R18

305/55R20

Diameter +0.2% · Good fit

285/60R20 → 275/70R18

285/60R20

Diameter +0.9% · Good fit

285/75R16 → 275/70R18

285/75R16

Diameter −1.0% · Good fit

285/70R17 → 275/70R18

285/70R17

Diameter −1.4% · Good fit

275/70R18 → 285/65R18

285/65R18

Diameter +1.8% · Good fit

275/70R18 → 285/70R18

285/70R18

Diameter −1.6% · Good fit

275/70R18 → 295/70R18

295/70R18

Diameter −3.2% · Marginal fit — proceed with care

275/70R18 → 305/60R18

305/60R18

Diameter +2.3% · Good fit

275/70R18 → 275/60R20

275/60R20

Diameter +0.5% · Good fit

275/70R18 → 275/65R20

275/65R20

Diameter −2.7% · Good fit

275/70R18 → 285/60R20

285/60R20

Diameter −0.9% · Good fit

275/70R18 → 285/65R20

285/65R20

Diameter −4.1% · Marginal fit — proceed with care

275/70R18 → 295/60R20

295/60R20

Diameter −2.3% · Good fit

275/70R18 → 305/55R20

305/55R20

Diameter −0.2% · Good fit

275/70R18 → 235/45R18

235/45R18

Diameter +25.9% · Not recommended

Common questions

What is the overall diameter of a 275/70R18 tire?
A 275/70R18 tire is about 33.16″ (842 mm) in overall diameter, with a sidewall height of 192.5 mm and a circumference of 104.17″.
How many revolutions per mile does a 275/70R18 tire turn?
A 275/70R18 turns roughly 608 revolutions per mile (378 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
What do the numbers in 275/70R18 mean?
275 is the tread width in millimetres, 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.