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Full Pipe Flow with Hazen Williams

Calculate full pipe flow with hazen williams with local equations, selectable units and supported inverse relationships.

  • Formula & worked example
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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

velocity = 1.6045382; discharge = 0.050408053. Values use the worked example unit selections.

v = 0.849 C Rh^0.63 S^0.54; Q = Av; Rh = A/P; S = drop/length

Worked example

Enter these known values and leave the other values blank.

Pipe diameter
20 cm
Material
Plastic
Pipe length
100 m
Drop
1 m
Hazen–Williams coefficient C
150
Flow velocity
1.6045 m/s
Flow discharge
0.05041 mÂł/s

Assumptions and limitations

  • This is Hazen-Williams for a full circular water pipe in SI, despite the captured roughness field being named manning. Preset coefficients are nominal scenario values and depend on pipe condition. It is not the Manning equation or a pump-pressure simulation.
  • Unit selectors convert known physical quantities. Leave a supported unknown blank; derived inverse branches are limited by the stated model and available captured equations.

Common questions

What does this calculation assume?

This is Hazen-Williams for a full circular water pipe in SI, despite the captured roughness field being named manning. Preset coefficients are nominal scenario values and depend on pipe condition. It is not the Manning equation or a pump-pressure simulation.

Can I solve for an input?

Where the captured model supplies an inverse, leave that quantity blank and enter the remaining known quantities. A positive square-root or principal trigonometric inverse may represent only one of multiple mathematical branches.

Which unit should I use for the worked example?

The example uses the initial metric unit selection beside each field. Change a unit using its selector to convert the same known quantity; switching a unit does not change the underlying physical value.

References

Restrict the physical model to non-singular dimensions and stated principal inverse branches; discrete gear/fringe counts are exact integers. Volumetric flow rates use exact US or imperial fluid-volume definitions and exact seconds per minute, hour and day.

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