P305/40R23 in inches

P305/40R23 — what does it mean?

• P means "passenger car"
• 305 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
• 23 is a wheel diameter (or rim) in inches

How to convert P305 40R23 to inches?

First of all, we need to divide 305 mm (width) by 25.4 (mm to inch conversion), which will give us a width of 12″. Then, 40% of the 12″ will result in 4.8″ sidewall.

To get the total height or tire diameter, we need to sum the 23″ rim diameter with two of the sidewall heights. It will result in a 32.6″ total tire diameter (or height).

For your convenience, below is a table for P305/40R23 conversion to inches:

Alternatives to a P305/40R23 tire

If you're looking to upsize your P305 40R23 tires, try to stay within 3% deviation of an overall diameter for safety reasons.