Reference volume for soil physical and chemical characteristics of soil samples is often based on soil core extraction. At the aggregate level, however, volume determination is more difficult and fraught with greater uncertainty due to irregular shapes. Our objective was to identify a method that best described relevant variables in aggregates. For this purpose, we compared four methods to determine the possibilities and limitations in acquiring those variables: paraffin coating and submerging, automated pycnometer, three-dimensional laser scanner, and x-ray microcomputed tomography. All methods gave reliable results for aggregate volume, but the pycnometer and three-dimensional laser scanner slightly overestimated the volume. The key benefits of the three-dimensional laser scanner and x-ray microtomography are the gain of additional parameters such as surface roughness, axial ratios, and interaggregate pore volumes. These characteristics may be of interest for further questions such as aggregate stability or accessibility of sorption surfaces.