Decoded notation
285 mm / 40% / R / 18 in
Popular Tire Sizes
285/40R18 Tire Size — Dimensions & Revs
Decode 285/40R18 and calculate nominal width, sidewall, overall diameter, circumference and revolutions.
Calculated dimensions are nominal values based on tire-size notation; actual measured dimensions vary.
Width285 mm
Sidewall height114.0 mm
Rim diameter18 in
Overall diameter685.2 mm
Overall diameter26.98 in
Circumference2152.6 mm
Revolutions per mile747.6
Revolutions per km464.6