The effective dose obtained by a patient on X-ray diagnostic studies may be determined by the Russian and foreign devices that measure the product of the absorbed dose by the radiation area while using the transition factors presented. They are calculated by the published data on the surface and effective doses per exposure unit, which are obtained on the phantoms by thermoluminescence dosimetry by taking into account the area of radiation, anode voltage, and projection, which characterize the standard conditions for performing basic X-ray diagnostic studies of adults and children (5 age groups). In the anode voltage range 40-120 kV, the factors are 10(-4) to 2.10.cm2) with errors of about +/- 32%.