The article presents a mathematical relationship between cost, profit and yield, presents a mechanism for the relationship of yield and the cost of grape production. The dependence of the yield of profit per unit of area and unit of production on the level of yield is shown; a formula for calculating marginal profit per unit of production depending on the level of yield is also presented. It is emphasized that a higher economic effect can be achieved due to an increase in yield per 1 centner/ha in the range of low field productivity. Thus, the yield range can be conditionally divided into 3 zones: the first zone is characterized by high economic returns with an increase in yield by 1 centner / ha, the second zone is moderate, and the third zone is low elasticity. It is shown that with an increase in fixed costs aimed at increasing yields, it must comply with the rule: the ratio of fixed costs to yields should not exceed the value of the specific marginal income. All of the above dependences are graphically presented.