This Molecular Formula Calculator determines the molecular formula of a compound based on its empirical formula and molar mass. By inputting the mass of the empirical formula and the molar mass of the actual molecule, the calculator divides the molar mass by the empirical formula mass and rounds to the nearest whole number to find the multiplier nnn. The molecular formula is then obtained by multiplying the subscripts in the empirical formula by this factor, providing the exact composition of the molecule.