Introduction: The COVID-19 pandemic is causing management difficulties in the Tunisian healthcare system inventory management and the supply of Personal Protective Equipment (PPE). Aim: Calculate the number of PPE needed for MAMI Hospital Ariana (dedicated hospital to COVID patients) to avoid stock-outs. Methods: This study proposed a calculation method of the PPE needs for the intensive care and pneumology departments. We developed a mathematical formulation of the number of PPE needed according to the number of visits per medical and other teams, their types, the number of patients, and the validity of each type of PPE. Results: Considering as input data: the number of visits for the different intervening teams (medical, paramedical, worker or other), the capacity of the different services (number of beds), the average length of stay of patients, the validity duration of an equipment and urgent visits, the developed model generates the required number of PPE (especially surgical masks, FFP2 masks, disposables gowns and coveralls). This allows to calculate the number of personal protective equipment (PPE) needed by the Mami hospital’s pharmacy in this period of COVID-19 crisis. Conclusion: Our configurable application allowed us to calculate PPE requirements for the intensive care and pneumology departments and estimate their use duratio