The general management accounting system is now outdated because the information generated by the system arrives too late or too distorted to be relevant to managers' planning and control decisions, moreover, the system is based on simplistic and arbitrary methods and fails to reflect accurate product costs. Entities use managerial accounting techniques, which include both financial and non-financial information, as tools in obtaining useful information throughout the technological processes. By using these methods, the aim is to ensure efficiency in the operations carried out. The present work has as its main objective, the detailed highlighting of the role of cost calculation in the substantiation of managerial decisions, but also of the process of drawing up budgets elaborated at the company level in order to optimize profit and to substantiate optimal decisions.