Free WACC Calculator

What is the Weighted Average Cost of Capital (WACC)?

The Weighted Average Cost of Capital (WACC) Calculator is a free online tool that helps businesses and financial analysts compute the blended cost of financing from equity and debt. By applying the WACC formula, this cost of capital calculator quickly reveals the minimum rate of return a company must achieve to create value for its investors. Understanding WACC is a cornerstone of corporate finance and company valuation, as it serves as a critical benchmark for investment decisions.

Why Capital Has a Cost

Every company needs capital to fund operations, expansion, or new projects. This capital is raised from two primary sources: equity (shareholders' funds) and debt (borrowed money). Each source carries a specific cost:

• Cost of debt: The interest rate paid on loans or bonds. For example, borrowing $100 at 8$108, so the cost of debt is 8% before taxes.
• Cost of equity: The return that shareholders expect for bearing the risk of investing. It is less tangible than debt cost, but if a company fails to deliver expected returns, shareholders may sell their shares, driving down the stock price and overall company value.

Because equity and debt are used together, their costs must be combined into a single metric that reflects the overall cost of capital. This is where WACC comes in.

The WACC Formula

The standard WACC formula is:

$$\text{WACC} = \frac{E}{E + D} \times C_e + \frac{D}{E + D} \times C_d \times (1 - T)$$

• $E$ = Market value of equity
• $D$ = Market value of debt
• $C_e$ = Cost of equity (expressed as a decimal)
• $C_d$ = Cost of debt (expressed as a decimal)
• $T$ = Corporate tax rate (as a decimal)

The $(1 - T)$ term accounts for the tax shield on interest payments: because interest expense is deductible, the effective after‑tax cost of debt is lower than the stated interest rate.

Step‑by‑Step Calculation Example

Let’s work through a concrete example to see how WACC is computed.

Company inputs:

Item	Value
Equity (market value)	$700,000
Debt (market value)	$500,000
Cost of equity	15% (0.15)
Cost of debt	8% (0.08)
Corporate tax rate	20% (0.20)

1. Determine the capital structure weights:

$$\text{Weight of equity} = \frac{700,000}{700,000 + 500,000} = \frac{700,000}{1,200,000} = 0.5833 \;(58.33\%)$$ $$\text{Weight of debt} = \frac{500,000}{1,200,000} = 0.4167 \;(41.67\%)$$

2. Apply the WACC formula:

$$\begin{aligned} \text{WACC} &= 0.5833 \times 0.15 + 0.4167 \times 0.08 \times (1 - 0.20) \\ &= 0.0875 + (0.4167 \times 0.064) \\ &= 0.0875 + 0.02667 \\ &= 0.11417 \quad \text{or} \quad 11.42\% \end{aligned}$$

The table below summarises the weighted costs:

Source	Weight	Before‑tax Cost	After‑tax Cost	Weighted Cost
Equity	58.33%	15%	15%	8.75%
Debt	41.67%	8%	6.4% (8% × (1‑0.20))	2.67%
WACC				11.42%

Thus, the company’s weighted average cost of capital is 11.42%.

How to Interpret WACC

The WACC is a hurdle rate: any investment or project should generate a return higher than the WACC to increase shareholder value. If the expected internal rate of return (IRR) is above 11.42%, the project is value‑adding; if it is below, the company would destroy value by undertaking it.

WACC also plays a central role in company valuation. It is often used as the discount rate in Discounted Cash Flow (DCF) models to calculate the present value of future cash flows. For this reason, the WACC calculator is a valuable corporate finance calculator for analysts, investors, and business owners alike.

Important Considerations

• Market values vs. book values: The formula should use the market values of equity and debt (not book values) to reflect the current cost of capital.
• Constant capital structure: WACC assumes the company’s capital structure remains stable over the analysis period.
• Risk adjustments: For projects with different risk profiles, the WACC may need to be adjusted (e.g., using a project‑specific discount rate).

By mastering the WACC calculation, companies can make more informed financing and investment decisions, ultimately driving long‑term value creation.