225/55R18 tire size breakdown:
225 – Tire width is 225 mm.
55 – Aspect ratio; the sidewall height is 55% of 225 mm, which is 123.8 mm (about 124 mm).
R – Radial tire construction.
18 – Fits an 18-inch wheel (rim).
Approximate overall dimensions:
Sidewall height: 124 mm (4.9 inches)
Overall tire diameter: 705 mm (27.8 inches)
Circumference: 2,214 mm (87.2 inches)
This size is commonly used on sedans, crossovers, and compact SUVs, offering a good balance of comfort, handling, fuel efficiency, and all-around performance.