A new technique is described for calculating molecular photodissociation rates using a novel empirical formulation. This technique is shown to be applicable for stratospheric photochemical modeling and atmospheric photochemical systems in general. The two basic independent variables that control photodissociation rates in the atmosphere are the column abundances of ozone and molecular oxygen; these are the main absorbers that control solar ultraviolet radiation in the atmosphere. Hence they are the key variables used to parameterize photodissociation processes. In this approach, the spectral integrals normally associated with photodissociation rate calculations are eliminated by substituting for the integrals empirical functions that depend only on the column abundances of O2 and O3. The particular empirical functions adopted here related to the curve of growth for the transmission of radiation through absorbing media, particularly through spectrally highly structured absorbers. The simple expressions that we derived can be applied to calculate photodissociation rates at most solar zenith angles for a wide variety of molecular species, including O2, O3, NO2, HO2, H2O, H2O2, N2O5, HNO3, N2O, HNO2, CO2, CH2O, SO2, OCS, HCl, CF2Cl2, CFCl3, CCl4, CH3Cl, ClO, ClO2, OClO, ClONO2, HOCl, CH3Br, BrNO3, and CH4O2. The accuracy and applicability of the empirical formulas, corrections for radiation scattering effects, variations in the solar ultraviolet spectrum, and temperature variations, are discussed.¿ 1997 American Geophysical Union