T175/90R18 in inches

How tall is a T175 90R18 tire?

When converted to inches, the equivalent of a T175/90R18 tire size is 30.4x6.9R18. It means that:

  • height overall (or diameter) is 30.4 inches
  • tread width is 6.9 inches
  • wheel diameter is 18 inches

Learn more

T175/90R18 tire size in inches
T175/90R18 tire size chart

T175/90R18 tire size in inches

T175/90R18 Height / overall diameter: 30.4 inches
Height / overall diameter
30.4 inches
T175/90R18 Tread width: 6.9 inches
Tread width
6.9 inches
T175/90R18 Sidewall: 6.2 inches
Sidewall
6.2 inches
T175/90R18 Wheel diameter: 18 inches
Wheel diameter
18 inches
T175/90R18 Circumference: 95.5 inches
Circumference
95.5 inches
T175/90R18 Revolutions: 665 per mile
Revolutions
665 per mile

T175/90R18 — what does it mean?

  • T means "temporary"
  • 175 stands for tread width in millimeters
  • 90 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

T175/90R18 tire code
T175/90R18 tire code

How to convert T175 90R18 to inches?

First of all, we need to divide 175 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 6.9″. Then, 90% of the 6.9″ will result in 6.2″ 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 30.4″ total tire diameter (or height).

For your convenience, below is a table for T175/90R18 conversion to inches:

Inches Metric
Overall diameter (height) 30.4″ 772 mm
Tread width 6.9″ 175 mm
Wheel diameter 18″ 772 mm
Sidewall height 6.2″ 158 mm
Circumference 95.5″ 2424 mm
Revolutions 665 / ml 413 / km

Alternatives to a T175/90R18 tire

If you're looking to upsize your T175 90R18 tires, try to stay within 3% deviation of an overall diameter for safety reasons.

Tire Tire diameter Width Wheel Size
265/60R18 30.6″ 0.16% 10.4″ 18″
275/60R18 31″ 0.48% 10.8″ 18″
275/55R18 29.8″ -0.49% 10.8″ 18″
245/60R18 29.6″ -0.66% 9.6″ 18″
255/65R18 31″ 0.48% 10″ 18″
285/55R18 30.4″ 0% 11.2″ 18″
235/65R18 30″ -0.33% 9.3″ 18″
255/60R18 30″ -0.33% 10″ 18″
T175/90D18 30.4″ 0% 6.9″ 18″
175/90R18 30.4″ 0% 6.9″ 18″