A set of 28 coal samples in the ASTM ranking range of anthracite to lignite have been used to establish correlations between mercury density (MDdmmf) and compositional parameters, such as the H/C, O/C and O/H atomic ratios. The absolute average percentage error and correlation coefficient of the developed correlations (Eqs. (1), (2) and (3)) are found to be 1.18; 0.96, 1.38; 0.95 and 1.57; 0.92 (dmmf basis) respectively.