205/55R18 in inches

How tall is a 205 55R18 tire?

When converted to inches, the equivalent of a 205/55R18 tire size is 26.8x8.1R18. It means that:

  • height overall (or diameter) is 26.8 inches
  • tread width is 8.1 inches
  • wheel diameter is 18 inches

Learn more

205/55R18 tire size in inches
205/55R18 tire size chart

205/55R18 tire size in inches

205/55R18 Height / overall diameter: 26.8 inches
Height / overall diameter
26.8 inches
205/55R18 Tread width: 8.1 inches
Tread width
8.1 inches
205/55R18 Sidewall: 4.4 inches
Sidewall
4.4 inches
205/55R18 Wheel diameter: 18 inches
Wheel diameter
18 inches
205/55R18 Circumference: 84.2 inches
Circumference
84.2 inches
205/55R18 Revolutions: 753 per mile
Revolutions
753 per mile

205/55R18 — what does it mean?

  • 205 stands for tread width in millimeters
  • 55 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

205/55R18 tire code
205/55R18 tire code

How to convert 205 55R18 to inches?

First of all, we need to divide 205 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 8.1″. Then, 55% of the 8.1″ will result in 4.4″ 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 26.8″ total tire diameter (or height).

For your convenience, below is a table for 205/55R18 conversion to inches:

Inches Metric
Overall diameter (height) 26.8″ 681 mm
Tread width 8.1″ 205 mm
Wheel diameter 18″ 681 mm
Sidewall height 4.4″ 113 mm
Circumference 84.2″ 2138 mm
Revolutions 753 / ml 468 / km

Alternatives to a 205/55R18 tire

If you're looking to upsize your 205 55R18 tires, try to stay within 3% deviation of an overall diameter for safety reasons.

Tire Tire diameter Width Wheel Size
245/45R18 26.6″ -0.18% 9.6″ 18″
235/45R18 26.4″ -0.37% 9.3″ 18″
275/40R18 26.6″ -0.18% 10.8″ 18″
135/80R18 26.6″ -0.18% 5.3″ 18″
145/80R18 27.2″ 0.36% 5.7″ 18″
155/70R18 26.6″ -0.18% 6.1″ 18″
165/70R18 27.2″ 0.36% 6.5″ 18″
185/55R18 26″ -0.78% 7.3″ 18″
205/50R18 26.2″ -0.59% 8.1″ 18″
T185/55R18 26″ -0.78% 7.3″ 18″