Article / Updated 03-26-2016
The cost of using external funds, or the cost of debt capital, is the interest rate you must pay lenders. However, because interest expenses are tax deductible, the after-tax cost of debt, kd, is the interest rate, r, multiplied by 1 minus the firm’s marginal tax rate, t, or
You’ve decided to finance a capital investment by issuing bonds that have a 6 percent annual interest rate.