TireSizeCheck

235/50R18

Common fitments: Equinox, Tiguan, CX-5

Overall diameter

27.25″

692 mm

Sidewall height

4.63″

117.5 mm

Tread width

235 mm

9.3″

Circumference

85.61″

7.1 ft

Revs per mile

740

460 per km

Wheel diameter

18″

aspect ratio 50%

Cross-section

Overall diameter
27.25″
Sidewall (each side)
4.63″
Wheel
18″

235/50R18 compared with other sizes

All 36 practical swaps involving 235/50R18 — diameter change, speedometer impact and a fit verdict for each.

235/50R18 → 215/65R16

215/65R16

Diameter +0.9% · Good fit

235/50R18 → 235/60R16

235/60R16

Diameter +0.6% · Good fit

235/50R18 → 235/55R17

235/55R17

Diameter +0.3% · Good fit

235/50R18 → 225/45R18

225/45R18

Diameter +4.9% · Marginal fit — proceed with care

235/50R18 → 235/45R18

235/45R18

Diameter +3.5% · Marginal fit — proceed with care

255/45R18 → 235/50R18

255/45R18

Diameter −0.8% · Good fit

245/45R18 → 235/50R18

245/45R18

Diameter −2.1% · Good fit

235/45R18 → 235/50R18

235/45R18

Diameter −3.4% · Marginal fit — proceed with care

235/55R18 → 235/50R18

235/55R18

Diameter +3.4% · Marginal fit — proceed with care

235/55R17 → 235/50R18

235/55R17

Diameter −0.3% · Good fit

235/45R19 → 235/50R18

235/45R19

Diameter +0.3% · Good fit

235/60R16 → 235/50R18

235/60R16

Diameter −0.5% · Good fit

255/40R18 → 235/50R18

255/40R18

Diameter −4.5% · Marginal fit — proceed with care

225/45R18 → 235/50R18

225/45R18

Diameter −4.7% · Marginal fit — proceed with care

225/60R18 → 235/50R18

225/60R18

Diameter +5.1% · Not recommended

265/35R20 → 235/50R18

265/35R20

Diameter +0.2% · Good fit

215/60R17 → 235/50R18

215/60R17

Diameter −0.3% · Good fit

255/40R19 → 235/50R18

255/40R19

Diameter −0.8% · Good fit

255/35R20 → 235/50R18

255/35R20

Diameter −0.8% · Good fit

235/50R18 → 245/45R18

245/45R18

Diameter +2.1% · Good fit

235/50R18 → 255/40R19

255/40R19

Diameter +0.8% · Good fit

235/50R18 → 275/40R19

275/40R19

Diameter −1.5% · Good fit

235/50R18 → 245/35R20

245/35R20

Diameter +1.9% · Good fit

235/50R18 → 255/35R20

255/35R20

Diameter +0.8% · Good fit

235/50R18 → 215/70R16

215/70R16

Diameter −2.1% · Good fit

235/50R18 → 225/65R16

225/65R16

Diameter −1.0% · Good fit

235/50R18 → 215/60R17

215/60R17

Diameter +0.3% · Good fit

235/50R18 → 225/60R17

225/60R17

Diameter −1.4% · Good fit

235/50R18 → 225/60R18

225/60R18

Diameter −4.8% · Marginal fit — proceed with care

235/50R18 → 235/55R18

235/55R18

Diameter −3.3% · Marginal fit — proceed with care

235/50R18 → 255/40R18

255/40R18

Diameter +4.7% · Marginal fit — proceed with care

235/50R18 → 255/45R18

255/45R18

Diameter +0.8% · Good fit

235/50R18 → 235/45R19

235/45R19

Diameter −0.3% · Good fit

235/50R18 → 245/40R20

245/40R20

Diameter −1.7% · Good fit

235/50R18 → 265/35R20

265/35R20

Diameter −0.2% · Good fit

235/50R18 → 275/35R20

275/35R20

Diameter −1.2% · Good fit

Common questions

What is the overall diameter of a 235/50R18 tire?
A 235/50R18 tire is about 27.25″ (692 mm) in overall diameter, with a sidewall height of 117.5 mm and a circumference of 85.61″.
How many revolutions per mile does a 235/50R18 tire turn?
A 235/50R18 turns roughly 740 revolutions per mile (460 per kilometre). This is the number that determines speedometer and odometer accuracy when you change tire size.
What do the numbers in 235/50R18 mean?
235 is the tread width in millimetres, 50 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 235 × 50% = 117.5 mm tall.