Telephone: 0116 240 1500

Copely Developments Ltd
Thurmaston Lane,

Pressure Drop Calculator

Metric Imperial

With this tool, it is possible to easily calculate the pressure drop of fluids moving through a tube or pipe. There are two versions of the tool available, allowing you to use the Pipe Roughness Coefficient for a number of materials or if you have the roughness measurement of the pipe, then that can be entered on the advanced version, as well as the fluid density and velocity.

If you need help working out the Flow Rate, take a look at our Flow Rate Calculator.

How to use: Enter the information about the pipe to work out the pipes pressure drop.

Need more options? Switch to the advanced view

Pressure Loss

0.00 kPa

The simple version of the pressure drop calculator uses the following equation to calculate pressure loss due to pipe friction:

Pressure Loss = 4.53 x Pipe Length x (((Flow Rate / Pipe Coefficient)1.852) / (Pipe Diameter)4.857)

The advanced version of the calculator has a number of steps to work out the pressure.

Friction Factor = 1.14 + 2log10(Pipe Diameter / Pipe Roughness) – 2

Frictional Head Loss = Friction Factor * (Pipe Length / Pipe Diameter) * (Average Velocity2/(2*32.17))

Frictional Pressure (PSF) = Fluid Density * 32.17 * Frictional Head Loss

Frictional Pressure (PSI) = Frictional Pressure (PSF) / 144

Common Pipe Roughness Figures

MaterialRoughness (mm)
Aluminum and Lead0.001 – 0.002
Asphalted Cast Iron0.012
Concrete0.3 – 3
Corroding Cast Iron1.5 – 2.5
Drawn Brass, Drawn Copper0.0015
Galvanized Iron0.015
Galvanized Steel0.15
New Cast Iron0.25 – 0.8
Ordinary Wood5
PVC and Plastic Pipes0.0015
Riveted Steel0.9 – 9
Rusted Steel0.15 – 4
Stainless Steel0.015
Steel Commercial Pipe0.045 – 0.09
Stretched Steel0.015
Weld Steel0.045
Well Planed Wood0.18 – 0.9
Worn Cast Iron0.8 – 1.5

Remember, if you would like some assistance in choosing the right hose for your application or sector, please feel free to contact one of our helpful team members on 0116 240 1500 or email