# Fish ladders: Number of falls

This tool is an aid for the pre-dimensioning of a fish ladder: it allows to calculate the missing value of the three quantities:

• the total fall ($$\Delta H_T$$) in m;
• the fall between basins ($$\Delta H$$) in m;
• the number of falls ($$N$$);

as well as the residual fall ($$\Delta H_R$$) in m.

## Formula

$\Delta H_T = \left ( \Delta H * N \right ) + \Delta H_R$