255/40R20 in inches

How tall is a 255 40R20 tire?

When converted to inches, the equivalent of a 255/40R20 tire size is 28x10R20. It means that:

  • height overall (or diameter) is 28 inches
  • tread width is 10 inches
  • wheel diameter is 20 inches

Learn more

255/40R20 tire size in inches
255/40R20 tire size chart

255/40R20 tire size in inches

255/40R20 Height / overall diameter: 28 inches
Height / overall diameter
28 inches
255/40R20 Tread width: 10 inches
Tread width
10 inches
255/40R20 Sidewall: 4 inches
Sidewall
4 inches
255/40R20 Wheel diameter: 20 inches
Wheel diameter
20 inches
255/40R20 Circumference: 87.9 inches
Circumference
87.9 inches
255/40R20 Revolutions: 721 per mile
Revolutions
721 per mile

255/40R20 — what does it mean?

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

255/40R20 tire code
255/40R20 tire code

How to convert 255 40R20 to inches?

First of all, we need to divide 255 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 10″. Then, 40% of the 10″ will result in 4″ sidewall.

To get the total height or tire diameter, we need to sum the 20″ rim diameter with two of the sidewall heights. It will result in a 28″ total tire diameter (or height).

For your convenience, below is a table for 255/40R20 conversion to inches:

Inches Metric
Overall diameter (height) 28″ 711 mm
Tread width 10″ 255 mm
Wheel diameter 20″ 711 mm
Sidewall height 4″ 102 mm
Circumference 87.9″ 2233 mm
Revolutions 721 / ml 448 / km

Alternatives to a 255/40R20 tire

If you're looking to upsize your 255 40R20 tires, try to stay within 3% deviation of an overall diameter for safety reasons.

Tire Tire diameter Width Wheel Size
305/35R20 28.4″ 0.35% 12″ 20″
275/40R20 28.6″ 0.52% 10.8″ 20″
315/35R20 28.6″ 0.52% 12.4″ 20″
245/40R20 27.8″ -0.18% 9.6″ 20″
295/35R20 28.2″ 0.18% 11.6″ 20″
285/35R20 27.8″ -0.18% 11.2″ 20″
275/35R20 27.6″ -0.35% 10.8″ 20″
155/60R20 27.4″ -0.53% 6.1″ 20″
T165/60R20 27.8″ -0.18% 6.5″ 20″
175/55R20 27.6″ -0.35% 6.9″ 20″