Formula & Calculator
Weighted Average Cost of Capital (WACC)
Calculates a company's blended cost of financing from both equity and debt, weighted by their proportion of total capital.
Interpretation
WACC = (E/V)Re + (D/V)Rd(1−Tax). The average rate of return required by all investors. Used as discount rate in valuation and capital budgeting.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| WACC | Weighted average cost of capital | % |
| E | Market value of equity | currency |
| D | Market value of debt | currency |
| V | Total capital (E+D) | currency |
| Re | Cost of equity | % |
| Rd | Cost of debt | % |
| Tax Rate | Corporate tax rate | % |
What it means
WACC is the weighted average of the cost of equity (Re) and the after‑tax cost of debt (Rd), where weights are based on the market values of equity (E) and debt (D) in the capital structure (V = E + D). It represents the minimum return a company must earn on its existing assets to satisfy its investors. WACC is used as the discount rate in discounted cash flow (DCF) analysis, to evaluate investment projects, and to determine the optimal capital structure. Understanding WACC is critical for corporate finance professionals and investors to assess company value and financial performance.
Worked example
WACC – Two Detailed Examples
Real‑World| Parameter | Value |
|---|---|
| E | 600000 |
| D | 400000 |
| Re (%) | 12 |
| Rd (%) | 6 |
| Tax Rate (%) | 25 |
| Parameter | Value |
|---|---|
| E | 800000 |
| D | 200000 |
| Re | 10 |
| Rd | 5 |
| Tax | 21 |
Common mistakes
- WACC: Weighted average cost of capital – the overall required return for a company.
- E/V: Proportion of equity in the capital structure – market values, not book values.
- D/V: Proportion of debt – similarly market values.
- Re: Cost of equity (e.g., from CAPM).
- Rd: Cost of debt – the yield to maturity on existing debt.
- Tax rate: The corporate tax rate – the tax shield on debt makes its cost lower.
- Assumes: The company maintains a constant capital structure.
Applications
The Weighted Average Cost of Capital (WACC) is the average rate of return a company is expected to pay to all its security holders, weighted by the proportion of each financing source. It is used as the discount rate for project valuation and as a hurdle rate for investment decisions. Corporate finance professionals use WACC to evaluate capital structure, to assess the cost of raising new capital, and to determine whether projects will create shareholder value. By calculating WACC, companies can optimise their debt‑equity mix and minimise the cost of financing. This metric is essential for strategic planning, merger analysis, and performance evaluation.
- Project evaluation and capital budgeting
- Mergers and acquisitions valuation
- Optimal capital structure analysis
- Performance measurement (Economic Value Added)
- Financial modelling and forecasting
Frequently Asked Questions
WACC = (E/V) × Re + (D/V) × Rd × (1 − Tax Rate). It calculates the average rate of return a company must pay to its investors (both equity and debt) for funding its assets. It is a key metric for evaluating investment projects.
- E = market value of equity
- D = market value of debt
- V = E + D (total firm value)
- Re = cost of equity (e.g., from CAPM)
- Rd = cost of debt (yield to maturity)
Interest payments on debt are tax‑deductible, so the after‑tax cost of debt is lower than the pre‑tax rate. The tax shield reduces the effective cost of debt, lowering the WACC.
Commonly, the CAPM is used: Re = R_f + β × (R_m − R_f). Other models like the Dividend Discount Model (Gordon Growth) may also be used.
The formula weights the cost of equity and the after‑tax cost of debt by their respective market value proportions. It provides the overall required rate of return for the firm.
Since WACC represents the firm's overall cost of capital, it is the appropriate discount rate for projects that have the same risk as the firm's average project. It ensures that the project's return covers the cost of financing.
- It assumes the firm's capital structure is stable.
- It uses market values, which may be volatile.
- It does not account for project‑specific risk.
- It may not be appropriate for projects with different risk profiles.
Increasing debt (lower taxes) can lower WACC, but too much debt increases financial risk, raising the cost of equity and debt. There is an optimal capital structure that minimizes WACC.
Add a term for preferred stock: WACC = (E/V)×Re + (P/V)×Rp + (D/V)×Rd×(1−T), where P is the market value of preferred stock and Rp is its cost.
WACC is the firm‑wide cost of capital. For a specific project, you may adjust the discount rate to reflect its risk (e.g., using a risk‑adjusted WACC).