Optimal capital structure refers to a financial measurement that firms use to determine the best mix of debt and equity to maximize the wealth of firm. The structure is typically expressed as a debt-to-equity ratio. In this, the main aim is to maximize the value of the firm by lowering the capital cost.
Optimal capital structure is simple structure & easy to understand. One needs not to have in-depth knowledge to understand it. This structure makes the firm less dependent on creditors/investors. In optimum capital structure, debt-to-equity ratio is maintained so that the debt will be a reasonable proportion of the total capital employed in the business.