The thermophysical properties of nanofluids are the key deciding parameters for their applicability in various applications. The present work deals with the experimental study and regression analysis on the density of three categorical nanofluids Al2O3/EG, CuO/EG, and CeO2/EG. The experiments were conducted on Anton Paar (SVM 3000) over different concentration samples of 0.2, 0.5, 0.8, 1, and 1.5 vol% and temperature of 20–80℃. The experimental investigation reveals that the density of these nanofluids shows a linear variation over temperature and concentration. From this finding, a regression analysis has been conducted to set up the correlation for density with concentration and temperature. From regression analysis plane equation was found very suitable to fit over the experimental data sets. Four different equations for the individual categorical nanofluid have been developed which can predict the density very accurately. For this equation, there is no requirement of density data of particle and base fluid density to calculate the results for these equations.