Runoff
Rational & Steel Formula Calculator

Units

Blocks shown as
light blue are editable

duration of
rain t =


hr

drainage area
A =



percentage of
rain as direct runoff C =


%

Table 1.0,
Coefficient b =




Table 1.0,
Coefficient K =




Eq. 3,
rainfall intensity I =



Calculated Results

Eq. 1, peak
discharge Q =



Eq. 1, peak
discharge Q =



Eq. 1, peak
discharge Q =


