The literature contains a number of tabulations of conversion factors that permit the direct computation of dose equivalent to organs and tissues of the human body for exposure from external radiation sources. Notable among these are conversion factors normalized to external field quantities for full body exposure to monoenergetic photons, full body exposure to photons and electrons from specific radionuclides, partial body exposure to X-ray photons and X-ray spectra used in diagnostic medical radiation, and full body exposure to neutrons. This article surveys the current literature and advises the reader on the scope and sources of more extensive data tabulations.