245/45R18 Tire Size Specifications & Compatible Vehicles
Overall Diameter
677.7 mm
Section Width
245 mm
Sidewall Height
110.3 mm
Circumference
2129.1 mm
Revs/Mile
756
Rim Diameter
18"
Inch Equivalent
26.7x9.6R18
Rim Width (ETRTO)
7.0" – 9.0"
Compatible Vehicles
The following vehicles use 245/45R18 tires from the factory:
2025 Cadillac CT5 Premium Luxury 2024 Cadillac CT5 Premium Luxury 2021 Cadillac CT5 Premium Luxury 2020 Cadillac CT5 Premium Luxury 2025 Dodge Charger Sixpack 2025 Genesis G80 2.5T 2024 Genesis G80 2.5T 2023 Genesis G80 2.5T 2022 Genesis G80 2.5T 2021 Genesis G80 2.5T 2025 Infiniti Q50 Luxe 2024 Infiniti Q50 Luxe
Alternative Tire Sizes
These tire sizes are within 3% overall diameter of 245/45R18 and may be used as replacements:
Popular Comparisons
See how 245/45R18 compares to other common tire sizes:
Understanding 245/45R18
The tire size 245/45R18 means the tire has a section width of 245mm, an aspect ratio of 45% (the sidewall height is 45% of the width), and fits a 18-inch rim.
Sidewall Height = 245 x 0.45 = 110.3 mm
Overall Diameter = (110.3 x 2) + (18 x 25.4) = 677.7 mm
Circumference = 677.7 x π = 2129.1 mm
Overall Diameter = (110.3 x 2) + (18 x 25.4) = 677.7 mm
Circumference = 677.7 x π = 2129.1 mm
Frequently Asked Questions
The 245/45R18 tire size is used on 12 vehicle trims including the 2025 Cadillac CT5, 2024 Cadillac CT5, 2021 Cadillac CT5 and 9 more.
A 245/45R18 tire has an overall diameter of 677.7mm (26.7 inches). The sidewall height is 110.3mm, and the total circumference is 2129mm.
For 245/45R18 tires, the ETRTO recommended rim width is 8.0". The acceptable range is 7.0" minimum to 9.0" 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 245/45R18 677.7mm diameter. Compatible alternatives include 315/35R18, 205/60R17, 195/50R19. Use our Tire Size Calculator to compare any two sizes.