<p>The theory, computational modelling and data analysis of hydrodynamic and other solution properties of macromolecules and nanoparticles in dilute solution are nowadays well-established. Along this essay, we briefly present the variety of methods which are currently available for those purposes. Although such methods embody an important complexity, they are usually presented as user-friendly tools which can be used without previous knowledge of their foundations. Some understanding of classical concepts in which modern tools are based can result in a better, more profitable, use of them and a most adequate form of presenting and discussing their results. We describe the utility of employing a systematic way of handling data and results for the solution properties in terms of equivalent radii, which indeed provide an alternative to the raw properties in their use for structural determinations. They can also be employed in the design of simulation of experiments and data analysis procedures, like in analytical ultracentrifugation as we propose finally in this paper.</p>