Tire Size Calculator
Calculate tire sizes in inches or millimeters and find alternative sizes.
Inches
Millimeters
Results for 315/30R18 Tires
Diameter
25.4"
Width
12.4"
Sidewall
3.7"
Circumference
79.9"
Revs per mile
793
Alternate Tire Sizes
18"
14"
15"
16"
17"
19"
20"
Tire Size
Diameter
Width
Sidewall
Circumference
Revs per mile