Calculate WACC The Weighted Average Cost of Capital is sometimes called the Opportunity Cost of Capital because there is a cost of using financing Calculate the opportunity cost of capital for a firm with the following capital structure: 30% preferred stock, 50% common stock and 20% debt. The firms has a cost of debt of 6.32%, a cost of preferred stock equal to 10.7% and a 14.56% cost of common stock. The firm has a 26% tax rate. You answer should be entered as a %, for example 15.48%