Hazen-Williams Equation Calculator
Units
US
SI
Hazen-Williams C
—
Diameter, D
in
Length, L
ft
Flow, Q
gpm
Velocity, V
—
ft/s
Head loss, h
f
—
ft
$$ h_f = \frac{10.44 \, L \, Q^{1.852}}{C^{1.852} \, D^{4.87}} $$
US units: Q in gpm, D in inches, L and h
f
in ft. (SI uses 10.67 with Q in m³/s, D and L in m.)
via
PE-Calc — Hazen-Williams