An example study showed that there may be 70% difference in armour stone weight when Van der Meer (1988) and Van Gent et al. (2004) formulas are applied as recommended by "The Rock Manual: The use of rock in hydraulic engineering" (2007) with specific design constraints. In this paper, questions arise in the application of these formulas and their dependence on certain design constraints given in literature as mentioned in "The Rock Manual: The use of rock in hydraulic engineering" (2007) are discussed. Based on the results of this study, a new design flowchart that uses Van der Meer (1988) and Van Gent et al. (2004) formulations is proposed and tested by physical model experiments. Furthermore, a real case study in Aliaga, Izmir, Turkey is presented in order to indicate the importance of the new design flowchart.