How to calculate WACC

A calculation of a firm's cost of capital in which each category of capital is proportionately weighted. All capital sources - common stock, preferred stock, bonds and any other long-term debt - are included in a WACC calculation.

WACC is calculated by multiplying the cost of each capital component by its proportional weight and then summing:


WACC = E/(D+E)*[ rf + MRP*βL ] + D/(D+E)* rd*( 1 – t )

Where:
rf + MRP*βL = Re = cost of equity
rd = cost of debt
E = market value of the firm's equity
D = market value of the firm's debt
V = E + D
E/V = percentage of financing that is equity
D/V = percentage of financing that is debt
t = corporate tax rate

Broadly speaking, a company’s assets are financed by either debt or equity. WACC is the average of the costs of these sources of financing, each of which is weighted by its respective use in the given situation. By taking a weighted average, we can see how much interest the company has to pay for every dollar it finances.

A firm's WACC is the overall required return on the firm as a whole and, as such, it is often used internally by company directors to determine the economic feasibility of expansionary opportunities and mergers. It is the appropriate discount rate to use for cash flows with risk that is similar to that of the overall firm.

你都無answer 人 how to calculate the cost of debt, the cost of preferred stock and the cost of common stock?

Your book should have fomula for WACC, it is a easy calculation, you just need to fit in the figures and calculate the answer.