235/45R21 in inches

How tall is a 235 45R21 tire?

When converted to inches, the equivalent of a 235/45R21 tire size is 29.4x9.3R21. It means that:

  • height overall (or diameter) is 29.4 inches
  • tread width is 9.3 inches
  • wheel diameter is 21 inches

Learn more

235/45R21 tire size in inches
235/45R21 tire size chart

235/45R21 tire size in inches

235/45R21 Height / overall diameter: 29.4 inches
Height / overall diameter
29.4 inches
235/45R21 Tread width: 9.3 inches
Tread width
9.3 inches
235/45R21 Sidewall: 4.2 inches
Sidewall
4.2 inches
235/45R21 Wheel diameter: 21 inches
Wheel diameter
21 inches
235/45R21 Circumference: 92.3 inches
Circumference
92.3 inches
235/45R21 Revolutions: 686 per mile
Revolutions
686 per mile

235/45R21 — what does it mean?

  • 235 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
  • 21 is a wheel diameter (or rim) in inches

235/45R21 tire code
235/45R21 tire code

How to convert 235 45R21 to inches?

First of all, we need to divide 235 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 9.3″. Then, 45% of the 9.3″ will result in 4.2″ sidewall.

To get the total height or tire diameter, we need to sum the 21″ 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 235/45R21 conversion to inches:

Inches Metric
Overall diameter (height) 29.4″ 747 mm
Tread width 9.3″ 235 mm
Wheel diameter 21″ 747 mm
Sidewall height 4.2″ 106 mm
Circumference 92.3″ 2346 mm
Revolutions 686 / ml 426 / km

Alternatives to a 235/45R21 tire

If you're looking to upsize your 235 45R21 tires, try to stay within 3% deviation of an overall diameter for safety reasons.

Tire Tire diameter Width Wheel Size
245/40R21 28.8″ -0.51% 9.6″ 21″
245/45R21 29.6″ 0.17% 9.6″ 21″
255/40R21 29″ -0.34% 10″ 21″
255/45R21 30″ 0.5% 10″ 21″
265/40R21 29.4″ 0% 10.4″ 21″
275/35R21 28.6″ -0.71% 10.8″ 21″
275/40R21 29.6″ 0.17% 10.8″ 21″
285/35R21 28.8″ -0.51% 11.2″ 21″
285/40R21 30″ 0.5% 11.2″ 21″
295/35R21 29.2″ -0.17% 11.6″ 21″