Calculate the flow of water through a drainage grate. Weir and Orifice calculators are used to determine the inlet capacity in sag (ponding) condition to help choose the proper grate for your project. Below outlines the EJ equations used in our calculations.About Our Calculations
Q = Flow capacity (in cubic feet per second)
C = Orifice coefficient
A = Open area of grate (ft2 )
g = Acceleration due to gravity (32.2ft/sec2 )
d = Depth of water over grate (in feet)
Using an Orifice coefficient of 0.67 and correcting open area from square feet to square inches and depth of water from feet to inches, this equation simplifies to: THE ORIFICE EQUATION.