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Fluid Mechanics Calculators

Pipe Flow Calculator

Flow rate, velocity and pressure loss in a pipe using the Hazen-Williams equation.

Enter values

PVC 150, copper 140, steel 120, old iron 100

Results update as you type.

Result

Head loss

0.878 m

Pressure drop
8,608 Pa
Pressure drop (bar)
0.0861
Velocity
0.849 m/s
Loss per 100 m
1.756 m

About the Pipe Flow Calculator

Flow rate, velocity and pressure loss in a pipe using the Hazen-Williams equation.

Also known as: pipe flow rate, hazen williams, water pipe capacity, pressure loss in pipe.

How to use this calculator

  1. Enter inside diameter, pipe length, flow rate, hazen-williams c.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

Hazen-Williams: h_f = 10.67·L·Q^1.852 / (C^1.852·d^4.87)

Worked example

Using the values pre-filled in the calculator above:

  • Inside diameter = 50 mm
  • Pipe length = 50 m
  • Flow rate = 100 L/min
  • Hazen-Williams C = 140

the calculator returns:

  • Head loss: 0.878 m
  • Pressure drop: 8,608 Pa
  • Pressure drop (bar): 0.0861
  • Velocity: 0.849 m/s