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Mihsaba›Pipe Pressure Drop Calculator

Pipe Pressure Drop Calculator

Calculate straight-pipe pressure drop and head loss with the Darcy-Weisbach equation from friction factor, length, diameter, density and velocity.

Uses the entered Darcy friction factor directly; choose f consistently with Reynolds number and roughness.

How to use

The Darcy-Weisbach relation estimates pressure loss caused by wall friction in straight internal flow. This calculator separates dynamic pressure, pressure drop and head loss so the result is easier to audit.

  1. Enter Darcy friction factor f.
  2. Enter pipe length and inside diameter.
  3. Enter fluid density and mean velocity.
  4. Review pressure drop and head loss.

How it is calculated

ΔP=f(L/D)(ρv²/2); hf=ΔP/(ρg)

Example

For water at 1000 kg/m³ and 1.5 m/s in a 100 m pipe of 0.1 m diameter with f=0.02, pressure drop is about 22.5 kPa.

Important notes

The calculator does not infer friction factor or add elbows/valves. Use the Darcy friction factor, not the Fanning factor.

Frequently asked questions

Pressure drop vs head loss?

They express the same frictional energy loss in pressure and fluid-head units.

Are fittings included?

No, this version covers straight-pipe friction only.

Where does f come from?

Use a correlation or Moody-chart value consistent with Reynolds number and roughness.