This paper is based on the calculation of construction dimensions and technological parameters of the cupola furnace for a given chemical composition of gray cast iron melt in a furnace for a given production capacity. The cupola furnace was chosen for the production of gray cast iron melt due to its simple construction, lower fuel consumption compared to other units, the melting process as well as the furnace maintenance is simple, continuous melt production is ensured, and the furnace production capacity can be changed without significant changes in coke consumption per ton of melt. In the first, theoretical part, the basic function and division of the cupola furnaces, the construction features of its individual parts and the process zone in the working space of the furnace are described. In the second, calculation part of the work, the mass fraction of individual charge components per 100 kg of melt was calculated to obtain the chemical composition of gray cast iron marked EN-GJL-250, and then the total charge mass with the height of individual charge components in the furnace. For a given furnace capacity of 3 t / h, the construction calculation of the basic dimensions of the furnace and the air supply system was performed.