Absolute Hβ nebular fluxes are presented for a total of 97 planetary nebulae (PN) in the Magellanic Clouds. These new fluxes are compared with all previously published data. Nebular masses are derived from 54 objects and are found to lie mainly in the range of 0.01-0.35 M_sun_. A relationship between density and ionized mass (M_neb_) proportional to 1/n_e_) for a subset of the nebulae is used to show that these objects are optically thick. Another relationship between Hβ flux and nebular density is examined. The point at which the nebulae become optically thin is seen as a change in the slope of this curve. From these relationships a nebular mass-radius relation of the form M_neb_ proportional to R^3/2^ is found to apply to optically thick nebulae, while optically thin nebulae evolve at constant M_neb_.