What Is WACC?
WACC stands for Weighted Average Cost of Capital. It is the blended return a company must earn to satisfy all major capital providers, usually debt holders and equity investors.
In practical finance work, WACC is often used as a discount rate in valuation and capital budgeting. A lower WACC usually means cheaper financing and higher present values, while a higher WACC means the company or project must earn more to create value.
How to Calculate WACC
To calculate WACC, first estimate the market value of equity and the market value of debt. Then estimate the cost of equity, the cost of debt, and the corporate tax rate. Finally, weight those funding costs by their share in the capital structure and sum the results.
- Determine the capital structure using equity and debt values.
- Estimate cost of equity, often with CAPM.
- Estimate pre-tax cost of debt.
- Adjust debt for taxes using
(1 - t).
- Weight each component and add them together.
For most company-wide valuation work, market values are preferred over book values because they better reflect the current cost of capital in the market.
WACC vs Discount Rate
WACC is one specific type of discount rate, but not every discount rate is WACC. WACC is the blended financing cost of the firm, while a discount rate is the broader rate used to convert future cash flows into present value.
| Term |
Meaning |
Typical use |
| WACC |
Company-wide blended cost of capital |
DCF using firm-level cash flows |
| Discount rate |
Any rate used to discount future value |
Project, asset, or firm valuation depending on context |
If you are valuing the whole firm using operating cash flows, WACC is often the correct discount rate. If you are valuing a narrower or risk-adjusted project, a different discount rate may be more appropriate.
WACC in DCF Valuation
WACC is most often used in DCF valuation when discounting cash flows that belong to the whole firm, such as FCFF. In that setup, WACC reflects the blended return required by both debt and equity holders.
If you are evaluating project cash flows directly, you will often move from WACC to NPV and compare the project result with IRR. If you only need to discount a single future amount rather than a full corporate cash-flow stream, use the Present Value Calculator.
A common workflow is: estimate cost of equity with CAPM, combine it with after-tax cost of debt in WACC, then use that rate in a DCF or NPV model to judge whether the investment creates value.
WACC Calculator FAQ
What is WACC?
WACC (Weighted Average Cost of Capital) is the average rate a company pays for its financing, weighted between equity and debt. It represents the required return investors expect and is commonly used as a discount rate in valuation.
How do I calculate WACC?
Use the formula WACC = (E/V) × rE + (D/V) × rD × (1 - t). If preferred stock is included, add (P/V) × rP. Here V = E + D (+ P), based on market values.
When should I use WACC?
Use WACC as the discount rate in DCF valuation when cash flows represent the entire firm (FCFF). It is also used for capital budgeting, investment decisions, and setting hurdle rates.
What is a good WACC?
A “good” WACC depends on the industry, risk level, and market conditions. Lower WACC generally indicates cheaper financing and higher firm value, but it should always be compared to returns on investment or project IRR.
WACC vs discount rate: what is the difference?
WACC is a specific type of discount rate based on a company’s capital structure and cost of financing. A discount rate is a broader concept and can be adjusted above or below WACC depending on project risk.
What are common WACC calculation mistakes?
Common mistakes include using book instead of market values, applying inconsistent tax rates, mixing cash flow types (FCFF vs FCFE), and ignoring preferred stock when it is significant.
