In this calculator, we will use the “Rational Formula”  to determine the stormwater runoff                                                                                                

Stormwater Runoff in  m³ / sec                     Q             =             C*I*A / 3.6 *10⁶                                    

Here;                                                                                                                                    

C             Runoff coefficient                                                                                                                          

I               Rainfall intensity in mm/hr                                                                                                                          

A             Catchment area in m²   

Due to the Runoff coefficient value, A is further divided into these five categories:

Concrete paved area(A1)

Asphaltic paved area(A2)

Gravel paved area(A3)

Unpaved soil area(A4)

Grassy area (A5)

Another advantage of this calculator is that users have the option to input area in any of the following units i.e. hectare, acre, and sqm.