Weighted Average Cost Of Capital  WACC
Definition of 'Weighted Average Cost Of Capital  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 longterm debt  are included in a WACC calculation. All else equal, the WACC of a firm increases as the beta and rate of return on equity increases, as an increase in WACC notes a decrease in valuation and a higher risk.
The WACC equation is the cost of each capital component multiplied by its proportional weight and then summing: 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 Tc = corporate tax rate Businesses often discount cash flows at WACC to determine the Net Present Value (NPV) of a project, using the formula: NPV = Present Value (PV) of the Cash Flows discounted at WACC. 

Investopedia explains 'Weighted Average Cost Of Capital  WACC'
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. Need more WACC? Read Cost of Capital  Weighted Average Cost of Capital and Investors Need A Good WACC 
