One of the statistical models of warehouse operation is considered. The model is based on typical volumes of incoming and outgoing flows of stored goods. On the basis of a direct search, all possible options for warehouse inventory are determined. The probability of possible reserves is calculated from the distributions of typical volumes. Based on these data, a table of cumulative probabilities or an integral distribution law is constructed. On the basis of the assigned confidence probability, using the cumulative probabilities table, the projected stock of the warehouse is determined. For the case when there are no probabilities in the table, an analytical method is proposed equal to the cumulative one. The method is based on the similarity of the relations between the boundary values of the confidence probability and the values of the inventory corresponding to the boundaries of the confidence probability. An example of solving the problem of determining the projected stock of the warehouse.