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Fluid Mechanics Calculators

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.

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.

Pipe Flow 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