Leverage refers to a firm's use of fixed costs, whether operating costs or financial costs like interest, to magnify the effect of changes in sales or operating profits on profits. There are three main types of leverage:
1) Operating leverage is the use of fixed operating costs, which do not vary with sales. Higher operating leverage means profits are more sensitive to changes in sales.
2) Financial leverage is the use of fixed financing charges like interest on debt. It magnifies the effect of changes in operating profits on net profits.
3) Combined leverage considers the interaction of operating and financial leverage and their combined effect on profits and earnings per share. Firms seek an optimal level of leverage to maximize