Decoded notation
225 mm / 40% / R / 18 in
Popular Tire Sizes
225/40R18 Tire Size — Dimensions & Revs
Decode 225/40R18 and calculate nominal width, sidewall, overall diameter, circumference and revolutions.
Calculated dimensions are nominal values based on tire-size notation; actual measured dimensions vary.
Width225 mm
Sidewall height90.0 mm
Rim diameter18 in
Overall diameter637.2 mm
Overall diameter25.09 in
Circumference2001.8 mm
Revolutions per mile803.9
Revolutions per km499.5