The prediction of moisture transfer within concrete is necessary in order to evaluate its durability, because moisture transfer is related to shrinkage cracks and the transfer of chloride ions. Moisture transfer within concrete during drying has been analysed by many investigators using a non-linear diffusion equation. In the present paper, a comprehensive analytical procedure using a diffusion equation is established by comparing calculated results with experimental data for a wide range of concrete mix proportions. These experiments involved observing the effect of one-face drying and six-face drying on the water content profiles and mass decreases in prismatic specimens. The values of the coefficient required for the analysis are reported for a wide range of water/cement ratios, and the effect of these coefficients on the calculated results is discussed.