Wave propagation in highly porous materials has a well established theoretical background. Still there are parameters which require complex laboratory experimentation in order to find numerical values. This paper presents an effective method to calculate the tortuosity of aluminum foam using numerical simulations. The work flow begins with the acquisition of the foam geometry by means of a micro-CT scanner and further image segmentation and analysis. The elastodynamic wave propagation equation is solved using a velocity-stress rotated staggered finite-difference technique. The effective wave velocities are calculated and using the fluid and, aluminum effective properties, the tortuosity is determined. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)