TireSizeCheck

255/65R18

Common fitments: Pilot, Highlander, Atlas

Overall diameter

31.05″

789 mm

Sidewall height

6.53″

165.8 mm

Tread width

255 mm

10.0″

Circumference

97.55″

8.1 ft

Revs per mile

650

404 per km

Wheel diameter

18″

aspect ratio 65%

Cross-section

Overall diameter
31.05″
Sidewall (each side)
6.53″
Wheel
18″

255/65R18 compared with other sizes

All 37 practical swaps involving 255/65R18 — diameter change, speedometer impact and a fit verdict for each.

255/65R18 → 265/70R16

265/70R16

Diameter +1.5% · Good fit

255/65R18 → 265/60R18

265/60R18

Diameter +1.7% · Good fit

255/65R18 → 235/80R17

235/80R17

Diameter −2.4% · Good fit

255/65R18 → 245/75R17

245/75R17

Diameter −1.3% · Good fit

255/65R18 → 255/70R17

255/70R17

Diameter −0.0% · Good fit

255/65R18 → 275/65R17

275/65R17

Diameter −0.1% · Good fit

255/65R18 → 235/65R18

235/65R18

Diameter +3.4% · Marginal fit — proceed with care

255/65R18 → 245/60R18

245/60R18

Diameter +5.0% · Marginal fit — proceed with care

255/65R18 → 245/65R18

245/65R18

Diameter +1.7% · Good fit

255/65R18 → 255/60R18

255/60R18

Diameter +3.3% · Marginal fit — proceed with care

275/60R18 → 255/65R18

275/60R18

Diameter −0.2% · Good fit

285/60R18 → 255/65R18

285/60R18

Diameter +1.3% · Good fit

265/65R18 → 255/65R18

265/65R18

Diameter +1.6% · Good fit

245/65R18 → 255/65R18

245/65R18

Diameter −1.6% · Good fit

265/60R18 → 255/65R18

265/60R18

Diameter −1.7% · Good fit

255/70R18 → 255/65R18

255/70R18

Diameter +3.2% · Marginal fit — proceed with care

255/60R18 → 255/65R18

255/60R18

Diameter −3.2% · Marginal fit — proceed with care

275/65R18 → 255/65R18

275/65R18

Diameter +3.3% · Marginal fit — proceed with care

235/65R18 → 255/65R18

235/65R18

Diameter −3.3% · Marginal fit — proceed with care

255/70R17 → 255/65R18

255/70R17

Diameter +0.0% · Good fit

255/60R19 → 255/65R18

255/60R19

Diameter −0.0% · Good fit

255/55R20 → 255/65R18

255/55R20

Diameter −0.0% · Good fit

245/60R18 → 255/65R18

245/60R18

Diameter −4.8% · Marginal fit — proceed with care

285/65R18 → 255/65R18

285/65R18

Diameter +4.9% · Marginal fit — proceed with care

255/65R18 → 255/70R18

255/70R18

Diameter −3.1% · Marginal fit — proceed with care

255/65R18 → 265/65R18

265/65R18

Diameter −1.6% · Good fit

255/65R18 → 265/70R18

265/70R18

Diameter −4.8% · Marginal fit — proceed with care

255/65R18 → 275/60R18

275/60R18

Diameter +0.2% · Good fit

255/65R18 → 275/65R18

275/65R18

Diameter −3.2% · Marginal fit — proceed with care

255/65R18 → 285/60R18

285/60R18

Diameter −1.3% · Good fit

255/65R18 → 285/65R18

285/65R18

Diameter −4.7% · Marginal fit — proceed with care

255/65R18 → 255/60R19

255/60R19

Diameter +0.0% · Good fit

255/65R18 → 275/55R19

275/55R19

Diameter +0.5% · Good fit

255/65R18 → 255/55R20

255/55R20

Diameter +0.0% · Good fit

255/65R18 → 265/55R20

265/55R20

Diameter −1.4% · Good fit

255/65R18 → 285/50R20

285/50R20

Diameter −0.5% · Good fit

255/65R18 → 235/45R18

235/45R18

Diameter +17.9% · Not recommended

Common questions

What is the overall diameter of a 255/65R18 tire?
A 255/65R18 tire is about 31.05″ (789 mm) in overall diameter, with a sidewall height of 165.8 mm and a circumference of 97.55″.
How many revolutions per mile does a 255/65R18 tire turn?
A 255/65R18 turns roughly 650 revolutions per mile (404 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
What do the numbers in 255/65R18 mean?
255 is the tread width in millimetres, 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 255 × 65% = 165.8 mm tall.