The use of open cell foams with high specific surface area represents an important breakthrough in several industrial applications. The modeling of the three-dimensional structure of the open cell foams and the definition of relevant geometrical characteristic dimensions deserve fundamental investigations for the possible applications in chemical engineering. Based on experimental data given by X-ray tomography or by scanning electron microscopy, we can have a good description of some of the features of the foam (average cell aperture and strut diameter). However, these techniques are complex, burdensome and long. The main, goal of this work is to propose a new, simple and fast technique in order to estimate the main characteristic lengths (cell, pore and strut size) of the open cell foams. (C) 2014 Elsevier B.V. All rights reserved.