Iron ore sinter is the main iron-bearing charge in many blast furnaces for ironmaking. A certain porosity of the charge is required to allow the flow of the carbon monoxide-rich reduction gas. The porosity of an accumulation of porous particles is of two types: the interparticle porosity resulting from the voids in the bulk and the intraparticle porosity of the porous particles. In this study the different porosities for sinter were determined using simple methods: measurement of the skeleton density by liquid pycnometry, measurement of the bulk density and determination of the envelope volume of the particles. The average skeleton density of the investigated sinter particles was 4.38 ± 0.22 g/cm³ and the average intraparticle porosity was 0.216 ± 0.037. For both parameters no distinct size dependence was observed.