Enter the static pressure (psi), the friction pressure loss (psi), and the elevation gain or loss (psi) into the calculator to determine the Irrigation Pressure. 

Irrigation Pressure Formula

The following formula is used to calculate the Irrigation Pressure.

Pirr = SP – FP + EP

  • Where Pirr is the Irrigation Pressure (psi)
  • SP is the static pressure (psi) 
  • FP is the friction pressure loss (psi) 
  • EP is the elevation gain or loss (psi) 

How to Calculate Irrigation Pressure?

The following example problems outline how to calculate the Irrigation Pressure.

Example Problem #1

  1. First, determine the static pressure (psi). In this example, the static pressure (psi) is given as 150 .
  2. Next, determine the friction pressure loss (psi). For this problem, the friction pressure loss (psi) is given as  23 .
  3. Next, determine the elevation gain or loss (psi). In this case, the elevation gain or loss (psi) is found to be 34.
  4. Finally, calculate the Irrigation Pressure using the formula above: 

Pirr = SP – FP + EP

Inserting the values from above and solving yields: 

Pirr = 150 – 23 + 43 = 170 (psi)


Example Problem #2

Using the same method as above, determine the variables required by the equation. For this example problem, these are provided as:

static pressure (psi) = 52

friction pressure loss (psi) = 9

elevation gain or loss (psi) = 6

Enter these given values yields: 

Pirr = 52 – 9 + 6 = 49 (psi)