Anesthesiologists perform a broad spectrum of tasks. However, in many countries, there is no legal basis for personnel staffing of physicians in anesthesia. Also, the German diagnosis related groups system for refunding does not deliver such a basis. Thus, in 2006 a new calculation base for the personnel requirement that included an Excel calculation sheet was introduced by the German Board of Anesthesiologists(BDA) and the German Society of Anesthesiology and Intensive Care Medicine(DGAI), and updated in 2009 and 2015. Oriented primarily to organizational needs, in 2015, BDA/DGAI defined quantitative and qualitative cornerstones for personnel requirement of physicians in anesthesia, especially reflecting recent laws governing physician’s working conditions and competence in the field of anesthesia, as well as demands of strengthened legal rights of patients, patient care and safety. We present a workload-oriented model, integrating core working hours, shift work or standby duty, quality of care, efficiency of processes, legal, educational, controlling, local, organizational and economic aspects for calculating personnel demands. Auxiliary tables enable physicians to calculate personnel demands due to differing employee workload, non-patient oriented tasks and reimbursement of full-equivalents due to parental leave, prohibition of employment, or longterm illness. After 10 years of experience with the first calculation tool, we report the generalizable key aspects and items of a necessary calculation tool which may help physicians to justify realistic workload-oriented personnel staffing demands in anesthesia. A modular, flexiblenature of a calculation tool should allow adaption to the respective legal and organizational demands of different countries. Anesthesiologists perform a broad spectrum of tasks. There, no is legal basis for personnel staffing of physicians in anesthesia. Also, the German diagnosis related groups system for refunding does not deliver such a basis. Thus, in 2006 a new calculation base for the personnel requirement that included an Excel calculation sheet was introduced by the German Board of Anesthesiologists (BDA) and the German Society of Anesthesiology and Intensive Care Medicine (DGAI), and updated in 2009 and 2015. Oriented primarily to organizational needs, in 2015, BDA / DGAI defined quantitative and qualitative cornerstones for personnel requirement of physicians in anesthesia, especially reflecting recent laws governing physician’s working conditions and competence in the field of anesthesia, as well as demands as strengthened global legal rights of patients, patient care and safety We present a workload-oriented model, integrating core working hours, shift work or standby duty, quali ty of care, efficiency of processes, legal, educational, controlling, local, organizational and economic aspects for calculating personnel demands. Auxiliary tables enable physicians to calculate personnel demands due to differing employee workload, non-patient oriented tasks and reimbursement of full-equivalents due to parental leave, prohibition of employment, or longterm illness. After 10 years of experience with the first calculation tool, we report the generalizable key aspects and items of a necessary calculation tool which may help physicians to justify realistic workload-oriented personnel staffing demands in anesthesia. A modular, flexiblenature of a calculation tool should allow adaption to the respective legal and organizational demands of different countries.