275/40R18 Tire Size Specifications & Compatible Vehicles
Overall Diameter
677.2 mm
Section Width
275 mm
Sidewall Height
110.0 mm
Circumference
2127.5 mm
Revs/Mile
756
Rim Diameter
18"
Inch Equivalent
26.7x10.8R18
Rim Width (ETRTO)
8.5" – 11.0"
Alternative Tire Sizes
These tire sizes are within 3% overall diameter of 275/40R18 and may be used as replacements:
Popular Comparisons
See how 275/40R18 compares to other common tire sizes:
Understanding 275/40R18
The tire size 275/40R18 means the tire has a section width of 275mm, an aspect ratio of 40% (the sidewall height is 40% of the width), and fits a 18-inch rim.
Sidewall Height = 275 x 0.4 = 110.0 mm
Overall Diameter = (110.0 x 2) + (18 x 25.4) = 677.2 mm
Circumference = 677.2 x π = 2127.5 mm
Overall Diameter = (110.0 x 2) + (18 x 25.4) = 677.2 mm
Circumference = 677.2 x π = 2127.5 mm
Frequently Asked Questions
The 275/40R18 is a standard tire size. Check your vehicle door jamb sticker or owner manual to confirm compatibility.
A 275/40R18 tire has an overall diameter of 677.2mm (26.7 inches). The sidewall height is 110.0mm, and the total circumference is 2128mm.
For 275/40R18 tires, the ETRTO recommended rim width is 9.5". The acceptable range is 8.5" minimum to 11.0" 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 275/40R18 677.2mm diameter. Compatible alternatives include 175/70R17, 245/50R17, 195/50R19. Use our Tire Size Calculator to compare any two sizes.