Two simple formulas are given which enable the total mass absorption coefficient of air to be readily calculated. These formulas, which are derived from published theoretical values of the total coefficient, are applicable to the energy ranges 0.01 to 100 Mev and 0.05 to 10 Mev, and yield results which agree with the theoretical values to within about 5% and 1%, respectively. Comparison is made with values calculated from existing empirical formulas which cover energies up to about 1 Mev.