This new computing tool has been designed to help you perform preliminary calculations at the early stages of designing your armour facing. It is based on Hudson’s formula, which is recognised internationally for the dimensional design of artificial breakwater armour units.

In addition, this version of the tool includes a variation of KD depending on the seabed slope in front of the structure combined with the breaking or non-breaking nature of the waves (the KD reduction depending on the seabed slope is based on the results of physical scale model studies).

If parameters 9 and 10 (see table below) are entered, the calculator will automatically check the number of rows on the slope and recommend the most suitable unit size.


Click here to use CLI's calculator


List of input parameters:

List of output parameters:

The information generated by this calculator is provided for information purposes only, and must only be used as an initial approach.

Simulations may help to clarify the main parameters but cannot be used directly as the basis for the armour design. The designer remains entirely responsible for performing a complete analysis on his project and for the dimensional design of the armour.

CLI can provide assistance and advice at all stages of the design and, if necessary, give an opinion on issues likely to influence the final design.