The purpose of the article is to study the problem of measuring the functional limits of integrated agricultural formations in the region. The conducted research allowed us to determine the optimal size of a large agribusiness in the region. In particular, for the current economic conditions of the region, the most effective type of integration associations, their optimal size in terms of area and the average number of employees were determined. The conceptual provisions of the proposed algorithm and its practical conclusions can be used by regional authorities in order to form an optimal agricultural structure. The identification of the optimal size of modern integrated formations will contribute to the planned and sustainable growth of the welfare of rural workers, the accelerated implementation of the export-oriented strategy, providing a multiplicative effect on the basis of large-scale innovative and technological modernization of agricultural sectors. The algorithm of estimation of efficiency of functioning of the integrated agricultural formations of the region reveals advantages of agricultural producers in the region of medium size, freely adapting to changing conditions and deprived of the shortcomings of large integrated groups and small sector.