325/45R18 in inches

How tall is a 325 45R18 tire?

When converted to inches, the equivalent of a 325/45R18 tire size is 29.4x12.8R18. It means that:

  • height overall (or diameter) is 29.4 inches
  • tread width is 12.8 inches
  • wheel diameter is 18 inches

Learn more

325/45R18 tire size in inches
325/45R18 tire size chart

325/45R18 tire size in inches

325/45R18 Height / overall diameter: 29.4 inches
Height / overall diameter
29.4 inches
325/45R18 Tread width: 12.8 inches
Tread width
12.8 inches
325/45R18 Sidewall: 5.7 inches
Sidewall
5.7 inches
325/45R18 Wheel diameter: 18 inches
Wheel diameter
18 inches
325/45R18 Circumference: 92.3 inches
Circumference
92.3 inches
325/45R18 Revolutions: 686 per mile
Revolutions
686 per mile

325/45R18 — what does it mean?

  • 325 stands for tread width in millimeters
  • 45 is an aspect ration between the tread width and the sidewall in percents
  • R means that the tire has a radial construction
  • 18 is a wheel diameter (or rim) in inches

325/45R18 tire code
325/45R18 tire code

How to convert 325 45R18 to inches?

First of all, we need to divide 325 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 12.8″. Then, 45% of the 12.8″ will result in 5.7″ sidewall.

To get the total height or tire diameter, we need to sum the 18″ rim diameter with two of the sidewall heights. It will result in a 29.4″ total tire diameter (or height).

For your convenience, below is a table for 325/45R18 conversion to inches:

Inches Metric
Overall diameter (height) 29.4″ 747 mm
Tread width 12.8″ 325 mm
Wheel diameter 18″ 747 mm
Sidewall height 5.7″ 146 mm
Circumference 92.3″ 2346 mm
Revolutions 686 / ml 426 / km

Alternatives to a 325/45R18 tire

If you're looking to upsize your 325 45R18 tires, try to stay within 3% deviation of an overall diameter for safety reasons.

Tire Tire diameter Width Wheel Size
265/55R18 29.4″ 0% 10.4″ 18″
255/55R18 29″ -0.34% 10″ 18″
275/55R18 29.8″ 0.33% 10.8″ 18″
235/60R18 29.2″ -0.17% 9.3″ 18″
245/60R18 29.6″ 0.17% 9.6″ 18″
225/60R18 28.6″ -0.71% 8.9″ 18″
235/65R18 30″ 0.5% 9.3″ 18″
255/60R18 30″ 0.5% 10″ 18″
245/55R18 28.6″ -0.71% 9.6″ 18″
T175/80R18 29″ -0.34% 6.9″ 18″