Enter the offset distance (in) and the shrink per inch (in/in) into the Calculator. The calculator will evaluate the Conduit Shrink. 

Conduit Shrink Formula



  • CS is the Conduit Shrink (in)
  • OD is the offset distance (in)
  • SPI is the shrink per inch (in/in)

To calculate Conduit Shrink, multiply the offset distance by the shrink per inch.

How to Calculate Conduit Shrink?

The following steps outline how to calculate the Conduit Shrink.

  1. First, determine the offset distance (in). 
  2. Next, determine the shrink per inch (in/in). 
  3. Next, gather the formula from above = CS = OD * SPI.
  4. Finally, calculate the Conduit Shrink.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

offset distance (in) = 30

shrink per inch (in/in) = 0.67