In this talk the concept of the radiation protection quantities will be explained. An overview about the different types and different applications of phantoms in radiation protection and their use for the definition of the different quantities is used for this. The phantoms can serve as a basis for the current definition and the calculation of conversion coefficients for the protection quantities according to ICRP 116. For the definition, the ICRU tissue 4-element phantoms are used. In practise, the the ISO calibration phantom for the current operational quantities such as ISO water slab, PMMA rod etc can be used for the calibration of personal dosemeters.