Decoded notation
255 mm / 30% / R / 18 in
Popular Tire Sizes
255/30R18 Tire Size — Dimensions & Revs
Decode 255/30R18 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 height76.5 mm
Rim diameter18 in
Overall diameter610.2 mm
Overall diameter24.02 in
Circumference1917.0 mm
Revolutions per mile839.5
Revolutions per km521.6