225/45R18 Tire Size Specifications & Compatible Vehicles

660mm101mm225/45R18Width: 225mm (8.9")
Overall Diameter
659.7 mm
Section Width
225 mm
Sidewall Height
101.3 mm
Circumference
2072.5 mm
Revs/Mile
777
Rim Diameter
18"
Inch Equivalent
26x8.9R18
Rim Width (ETRTO)
6.5" – 8.5"

Compatible Vehicles

The following vehicles use 225/45R18 tires from the factory:

Alternative Tire Sizes

These tire sizes are within 3% overall diameter of 225/45R18 and may be used as replacements:

Popular Comparisons

See how 225/45R18 compares to other common tire sizes:

Understanding 225/45R18

The tire size 225/45R18 means the tire has a section width of 225mm, an aspect ratio of 45% (the sidewall height is 45% of the width), and fits a 18-inch rim.

Sidewall Height = 225 x 0.45 = 101.3 mm
Overall Diameter = (101.3 x 2) + (18 x 25.4) = 659.7 mm
Circumference = 659.7 x π = 2072.5 mm

Frequently Asked Questions

The 225/45R18 tire size is used on 36 vehicle trims including the 2025 BMW 3 Series, 2025 BMW 3 Series, 2024 BMW 3 Series and 33 more.
A 225/45R18 tire has an overall diameter of 659.7mm (26.0 inches). The sidewall height is 101.3mm, and the total circumference is 2073mm.
For 225/45R18 tires, the ETRTO recommended rim width is 7.5". The acceptable range is 6.5" minimum to 8.5" maximum. Using a rim outside this range can cause improper bead seating and unsafe handling.
Yes, as long as the replacement tire overall diameter is within 3% of the 225/45R18 659.7mm diameter. Compatible alternatives include 285/40R17, 295/30R19, 195/65R16. Use our Tire Size Calculator to compare any two sizes.

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