Maintenance of proportions between equity and debt capital ensures the necessary level of financial independence of enterprises and increases their efficiency. The study aimed to generalise and systematise scientific approaches to determination of the optimal capital structure of an enterprise, analyse their practical significance in modern business conditions, and substantiate the criteria for optimisation of the capital structure to ensure effective financial activity. The study used methods of theoretical generalisation, a systematic approach, economic and statistical, comparative, and regression analysis to substantiate the optimal capital structure of an enterprise. The study assessed and analysed the overall capital structure of agricultural enterprises and several specific cases. The density of the relationship between the net profit of an enterprise, the financial leverage ratio, and the share of equity, was determined using the regression analysis method, noting that an increase in the share of debt capital has a negative impact on the net profit of agricultural enterprises, which is determined by an increase in interest payments on loans and an increase in financial risks. The study determined the most rational ratio between equity and borrowed capital based on the example of specific enterprises, as it is impossible to determine a single optimal structure for the industry. The author’s vision of the problem of equity and borrowed capital ratio optimisation is proposed based on the following criteria: profitability of equity and the effect of financial leverage, which characterise the efficiency of capital use under different options for its structure. The practical significance of the study is determined by the applicatbility of the results in agricultural enterprises, providing effective tools for economic monitoring in the formation of a rational capital structure
enterprise; net profit; return on equity; debt capital; financial leverage effect