Broad Crested Weir Calculator

Broad Crested Weir Calculator

Estimate the discharge using: $$ Q = \frac{2}{3}\, L\, \sqrt{2g}\, h^{3/2} $$

* Enter the weir crest length and head in millimeters (mm). They will be converted to meters. The result is displayed in cubic meters per second (m³/s).

Step 1: Enter Parameters

e.g., 1000 mm (1 m)

e.g., 50 mm (0.05 m)

Formula: $$ Q = \frac{2}{3}\, L\, \sqrt{2g}\, h^{3/2} $$
with \( g = 9.81 \, \text{m/s}^2 \). (All inputs are converted to SI units.)