Online Hazen-Williams calculator
Below, you will find a Hazen-Williams calculator, which you can use to calculate the pressure loss in a pipe using the Hazen-Williams pressure loss equation. The equation we have used is based on the equation in EN 12845, BS 9251, NFPA 13 and NFPA 750.
This calculator uses metric units. So the pressure is in bar, flow in Litre per minute (L/min), and the internal pipe diameter (ID) is in millimetres (mm).
Hazen-Williams pressure loss
p = (6.05 × 10&sup5; / (C1.852 × d4.87)) × Q1.852 × L
Q
C
d
L
Pressure loss per metre
— bar/m
Total pressure loss
— bar
Velocity
— m/s
Enter your values above to see results.
Common C-factors (EN 12845)