Work out pipe friction loss instantly with clear inputs, formula shown and shareable results.
The Hazen-Williams equation gives head loss for water in full pipes: hf = 10.67 L Q^1.852 / (C^1.852 D^4.87) in SI units. Because diameter appears to the 4.87 power, going up one pipe size cuts the loss dramatically, which is why oversizing a long main usually pays for itself in pumping energy.
Hazen-Williams
hf = 10.67 L Q^1.852 / (C^1.852 D^4.87)
Pressure
kPa = head loss m x 9.807
hf = 10.67 L Q^1.852 / (C^1.852 D^4.87). The Hazen-Williams equation gives head loss for water in full pipes: hf = 10.67 L Q^1.852 / (C^1.852 D^4.87) in SI units.
For anything other than water near room temperature, or where the flow may be laminar. Hazen-Williams is an empirical water-only fit and drifts outside its calibration range.
This calculator takes 4 inputs: Flow rate, Internal diameter, Pipe length, Hazen-Williams C factor. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.