Decoded notation
255 mm / 55% / R / 18 in
Popular Tire Sizes
255/55R18 Tire Size — Dimensions & Revs
Decode 255/55R18 and calculate nominal width, sidewall, overall diameter, circumference and revolutions.
Calculated dimensions are nominal values based on tire-size notation; actual measured dimensions vary.
Width255 mm
Sidewall height140.3 mm
Rim diameter18 in
Overall diameter737.7 mm
Overall diameter29.04 in
Circumference2317.6 mm
Revolutions per mile694.4
Revolutions per km431.5