235/50R18 tire size

A 235/50R18 tire is 235 mm wide with a sidewall 50% of its width (117.5 mm), fits a 18-inch rim and has an overall diameter of 692 mm (27.3 in).

DimensionMetricImperial
Section width235 mm9.25 in
Sidewall height117.5 mm4.63 in
Rim diameter457.2 mm18 in
Overall diameter692.2 mm27.25 in
Circumference2,174.6 mm85.61 in
Revolutions460 per km740 per mile

Reading the size 235/50R18

235Width in mm50Aspect ratio (sidewall % of width)RRadial construction18Rim diameter in inches

The load index and speed rating (for example 91V) follow the size on the sidewall. Replacement tires should match or exceed the original load index and speed rating.

Alternative sizes within 3% of 235/50R18

A replacement size should stay within about 3% of the original diameter so the speedometer, ABS and transmission stay accurate. Always check clearance, load index and the vehicle manufacturer's approved sizes.

SizeDiameterDifferenceSpeedo reads 100 → actual
215/55R18694 mm+0.2%100.2Compare
235/45R19694 mm+0.3%100.3Compare
235/55R17690 mm-0.3%99.7Compare
215/60R17690 mm-0.3%99.7Compare
235/60R16688 mm-0.5%99.5Compare
255/40R19687 mm-0.8%99.2Compare
255/35R20686 mm-0.8%99.2
215/65R16686 mm-0.9%99.1

Compare 235/50R18 with any size →

Other 18-inch sizes