A three parameter description of fractal aggregates is derived from the pair correlation function of the monomeric units that compose the aggregate. The parameters describe the mass fractal scaling with linear size (the fractal dimension), the packing fraction density of the spherical monomers, and the overall shape of the aggregates. Values for these three parameters are determined for diffusion limited cluster aggregates (DLCAs) in three dimensions. The effects of these parameters are found in terms of measureable quantities in both real and reciprocal space. (C) 2012 Elsevier Inc. All rights reserved.