Enter the throw distance (ft) and the image width (ft) into the Throw Ratio Calculator. The calculator will evaluate and display the Throw Ratio. 

Throw Ratio Formula

The following formula is used to calculate the Throw Ratio. 

  • Where THR is the Throw Ratio ( )
  • TD is the throw distance (ft) 
  • IW is the image width (ft) 

To calculate the throw ratio, divide the throw distance by the image width.

How to Calculate Throw Ratio?

The following example problems outline how to calculate Throw Ratio.

Example Problem #1:

  1. First, determine the throw distance (ft).
    • The throw distance (ft) is given as: 10.
  2. Next, determine the image width (ft).
    • The image width (ft) is provided as: 8.
  3. Finally, calculate the Throw Ratio using the equation above: 


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

THR = 10 / 8 = 1.25 ( )

Example Problem #2: 

For this problem, the variables required are provided below:

throw distance (ft) = 8

image width (ft) = 4

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

THR = TD / IW = ?