Broad Crested Weir Calculator
Compute discharge Q (m³/s) from coefficient, width, and head.
Instructions
- Enter Cw (discharge coefficient) based on your weir calibration.
- Enter the effective crest width b and the upstream head H over the crest.
- Click Calculate to get Q in m³/s.
Formula
Q = Cw · b · H3/2
This simplified empirical equation is commonly used; coefficients depend on geometry and approach flow.
Common Questions
How do I get Cw?
From lab calibration, standards, or literature for your weir geometry and approach conditions.
Units?
Inputs in meters produce Q in m³/s. Use consistent SI units.