Enter the tire sidewall height (in) and the tire width (in) into the Tire Aspect Ratio Calculator. The calculator will evaluate and display the Tire Aspect Ratio. 

Tire Aspect Ratio Formula

The following formula is used to calculate the Tire Aspect Ratio. 

TAR = SH / W 

  • Where TAR is the Tire Aspect Ratio (height:width)
  • SH is the tire sidewall height (in) 
  • W is the tire width (in) 

How to Calculate Tire Aspect Ratio?

The following example problems outline how to calculate Tire Aspect Ratio.

Example Problem #1:

  1. First, determine the tire sidewall height (in). 
    • The tire sidewall height (in) is given as: 12.
  2. Next, determine the tire width (in). 
    • The tire width (in) is provided as: 15.
  3. Finally, calculate the Tire Aspect Ratio using the equation above: 

TAR = SH / W 

The values given above are inserted into the equation below and the solution is calculated:

TAR = 12 / 15  = .8 (height:width)


Example Problem #2: 

For this problem, the variables required are provided below:

tire sidewall height (in) = 13

tire width (in) = 16

Test your knowledge using the equation and check your answer with the calculator above.

TAR = SH / W  = ?