MAXScanner thermal & fluid engineering
Hazen-Williams Calculator — Water Pipe Flow & Head Loss
Estimate water-pipe head loss from flow, diameter, length and Hazen-Williams C coefficient using the SI form.
Last updated: September 17, 2026
Results
Enter valid positive pipe data
Formula, example and assumptions
h_f=10.67·L·Q^1.852/(C^1.852·D^4.87) in SI.
For a known water flow and pipe size, the result reports head loss, pressure-equivalent loss and velocity.
- Hazen-Williams is empirical and intended mainly for ordinary water-service conditions.
- Q is converted to m³/s and D to metres internally.
Frequently asked questions
What is the C coefficient?
C is an empirical roughness/condition coefficient; smoother pipe uses a higher C.
Darcy-Weisbach or Hazen-Williams?
Darcy-Weisbach is more general; Hazen-Williams is a convenient water-system correlation.