The design of self-compacting concrete (SCC) is a time consuming and expansive process. We propose a new method for designing SCC's from equivalent mortars. For the purpose of this research, we investigated four methodologies to design equivalent mortars. They are all based on the assumption that the fresh materials, mortar and concrete can both be described as Bingham fluids. Thus, the measure of the rheological parameters of the mortars can be directly related to the equivalent parameters in concrete. Good models exhibit the same sensitivity as concrete to temperature, choice of superplasticizer and w/c changes as concrete.