The packing density of a particulate mixture is an important aspect of materials sciences and engineering. The packing density of a mixture depends on several parameters. This study considers the combined effect of vibration frequency, size ratio and large particle volume proportion on packing density of binary spherical mixtures. When all other parameters are constant, the increase of vibration frequency increases the packing density to a maximum and further increase of vibration frequency decreases the packing density of a mixture. The relationship found to be following a 3rd order polynomial curve. The increase of size ratio decreases the packing density linearly. The increase of large particle volume proportion also increases the packing density to a maximum and further increase of large particle proportion reduces the packing density rapidly. This variation also follows a polynomial pattern. These relationships were analyzed to develop a model incorporating combined effect and design graphs were developed from the derived model. The design graphs can be easily used to determine the packing density for a given vibration frequency and given size ratio. (C) 2018 Elsevier B.V. All tights reserved.