Enter the total water needed (gallons) and the sprinkler flow rate (gallons/min) into the Calculator. The calculator will evaluate the Sprinkler Run Time. 

Sprinkler Run Time Formula



  • SRT is the Sprinkler Run Time (min)
  • TW is the total water needed (gallons)
  • FR is the sprinkler flow rate (gallons/min)

To calculate Sprinkler Run Time, divide the total water required by the sprinkler flow rate.

How to Calculate Sprinkler Run Time?

The following steps outline how to calculate the Sprinkler Run Time.

  • First, determine the total water needed (gallons). 
  • Next, determine the sprinkler flow rate (gallons/min). 
  • Next, gather the formula from above = SRT = TW / FR.
  • Finally, calculate the Sprinkler Run Time.
  • 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.

total water needed (gallons) = 500

sprinkler flow rate (gallons/min) = 4.6