We applied Monte Carlo calculations to determine the radiation dose absorbed in water phantoms. Monoenergetic incident x-ray beams with energies from 15 to 100 keV and phantom thicknesses from 5 to 20 cm were considered in this study. We calculated the spatial distributions of energy absorption in the phantom, the rad/R conversion factors, the average rad/R conversion factors, and the scatter-to-primary ratios of absorbed dose. We also compared the relative absorbed doses under various imaging conditions when the transmitted radiation produced a given optical density on radiographic film. The information provided will be useful for the estimation of radiation doses in various radiographic procedures.