The equation describing dynamic surface tension in aqueous media at constant surfactant concentration, (γ 0 - γ t )/(γ t - γ m ) = (t/t * ) n , where γ 0 is the surface tension of the solvent, γ t at time t, and γ m , at mesoequilibrium, and t * and n are constants, is transformed mathematically to a Frumkin-type equation, π t = π m /[1 + 3.73t n exp(-n ln t)], where π t and π m are the surface pressure at time t and mesoequilibrium, respectively, and t i is the time at the end of the induction (initial) period of the surface tension reduction. It is suggested that n is related to the difference between the energies of adsorption and desorption and that t i is related to the surface coverage during the induction period. More than 20 systems were studied, including anionic, nonionic, and zwitterionic surfactants. The value of n increases with increases in the hydrophobic character of the surfactant while t i increases with increases in the tightness of packing of the adsorbed molecules at the interface. There is a linear relationship between ln t i and ln (T i /C), where T i is the surface (excess) concentration at t i , with a slope of approximately 2, suggesting diffusion-controlled adsorption in all systems studied. Surface coverage at t i in all the systems studied was 0.62 ± 0.05 of the maximum possible, which suggests an explanation for the observation that surfactants with larger surface areas/molecule decrease surface tension more rapidly than similar molecules with smaller areas/molecule.