Dosimetric concepts and the definition of dose quantities for use in radiation protection were defined by the ICRP and the ICRU. Three types of quantities are of relevance for radiation protection purposes: basic physical quantities, protection quantities, and operational quantities. The physical quantities are universally accepted for the characterisation of radiation fields. These are defined in any point of the field, and the units are directly obtained by primary standards. The protection quantities form the basis for dose limitation. These quantities are not directly measurable. A set of measurable operational quantities provides, in general, a conservative estimate of the protection quantities. These operational quantities are recommended in routine monitoring of occupational exposure. The relation between these different types of quantities is discussed. In addition, the calibration procedure for dosemeters in terms of the operational quantities, including the use of calibration phantoms, is summarised.