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Calcimator

Water Pressure Calculator

Calculate static pressure from elevation, friction pressure loss, and resulting dynamic pressure at the outlet.

Inputs

ft
in
ft
GPM

Results

Pressure at Outlet

54 PSI

Elevation Loss4.33 PSI
Friction Loss1.67 PSI
Total Pressure Loss6 PSI
Water Velocity3.63 ft/s
How to Use This Calculator
  1. Enter Elevation Change (ft) — positive if the outlet is below the source, negative if above.
  2. Set Pipe Diameter (inches) and Pipe Length (ft).
  3. Enter Flow Rate (GPM) at the fixture.
  4. Review Dynamic Pressure at Outlet, Elevation Loss (psi), and Friction Loss (psi).
  5. If dynamic pressure is below 20 psi, consider a booster pump or larger pipe diameter.

How the result changes with Pipe Diameter

Pipe DiameterPressure at Outlet
0.8354.62 PSI
2.2655.66 PSI
3.9955.67 PSI
5.4255.67 PSI

What each input means

Elevation Change
Height difference from supply to outlet. Positive means water flows uphill.
Pipe Diameter
Interior diameter of the supply pipe.
Pipe Length
Total length of the pipe run.
Flow Rate
Expected water flow rate in gallons per minute.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Elevation Change = 10, Pipe Diameter = 0.75, Pipe Length = 100, Flow Rate = 5 = 4 input(s) provided
  2. Calculate Pressure at Outlet
    Pressure at Outlet
    54 = 54
  3. Calculate Elevation Loss
    Elevation Loss = Math
    4.33 = 4.33
  4. Calculate Friction Loss
    Friction Loss
    1.67 = 1.67

Engine last updated . Checked against 3 independently-derived tests — how we verify calculators.

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