Variability in the polydispersity of colloidal nanoparticles results in significant differences in the total number of nanoparticles available for the determination of their concentration, which ultimately affects their bioavailability and biodistribution. In the current work, we developed a novel algorithm, named Nanoparticle Polydispersity Corrector (NANoPoLC), which was shown to render a more realistic calculation of the actual nanoparticle concentration in solution.