About the WACC Calculator
The weighted average cost of capital (WACC) is the average return a company must earn to satisfy all of its investors — shareholders, lenders and preferred stockholders — weighted by how much of each type of capital it uses. It is the standard discount rate for valuing a business with a DCF and the hurdle rate for deciding whether a new project creates value.
Enter the market value of equity and debt (and preferred stock if any), the pre-tax cost of debt and your tax rate. For the cost of equity you can type a figure directly or build it with the capital asset pricing model (CAPM) from the risk-free rate, beta and equity risk premium. The calculator returns WACC, the capital weights, the after-tax cost of debt and each component’s contribution.
Use market values rather than book values where you can. Because interest is tax deductible, debt is cheaper after tax — but more debt also raises risk, so WACC is an estimate built on judgement, not a precise figure.
With the default inputs, the wacc is 8.49%. Change any value above to recalculate instantly.
How to use the wacc calculator
- 1Enter the market value of equity (share price × shares outstanding) and of debt.
- 2Add preferred stock if the company has any.
- 3Choose CAPM and enter the risk-free rate, beta and risk premium, or type a cost of equity directly.
- 4Enter the pre-tax cost of debt and the corporate tax rate.
- 5Use the WACC as the discount rate in DCF, NPV or payback analysis.
Formula and method
Each source of capital is weighted by its share of total capital V = E + D + P, using market values. The cost of debt is reduced by the tax rate because interest is generally deductible, while equity and preferred dividends are paid from after-tax profit and receive no deduction.
When you choose CAPM, the cost of equity is the risk-free rate plus beta times the equity risk premium: investors expect compensation for time (the risk-free rate) and for market risk scaled by how volatile the stock is relative to the market (beta). The result is the minimum return the business must earn on new investments of similar risk.
- E, D, P
- Market values of equity, debt and preferred stock
- V
- Total capital E + D + P
- Re
- Cost of equity
- Rd
- Pre-tax cost of debt
- T
- Corporate tax rate
- β
- Equity beta
- ERP
- Equity (market) risk premium
Worked examples
60/40 equity and debt, CAPM
CAPM gives 4.3% + 1.2 × 5.5% = 10.9% cost of equity. Debt at 6.5% costs 4.875% after a 25% tax deduction. WACC = 0.6 × 10.9% + 0.4 × 4.875% = 8.49%.
Direct cost of equity, US 21% tax
Equity is 60% of capital at 12%, contributing 7.2 points. Debt is 40% at 7% × (1 − 0.21) = 5.53%, contributing 2.212 points. WACC is 9.41%.
Including preferred stock
With $10M of capital, weights are 50% equity, 30% debt and 20% preferred. WACC = 0.5 × 13% + 0.3 × 6% × 0.75 + 0.2 × 8% = 6.5 + 1.35 + 1.6 = 9.45%.
Frequently asked questions
What is a good WACC?+
Lower is better for the company because capital is cheaper, but WACC mainly reflects risk. Stable, large companies often have WACCs in the mid-to-high single digits, while small or high-growth companies can be well above 10%.
Why is the cost of debt multiplied by (1 − tax rate)?+
Interest payments are usually tax deductible, so each dollar of interest reduces taxable income. The effective cost to the company is therefore the interest rate times one minus the tax rate.
Should I use market or book values for the weights?+
Market values are preferred because they reflect what investors would pay today. Book values are a fallback for private companies or debt that does not trade, but they can distort the weights.
How do I estimate the cost of equity?+
CAPM is the most common approach: risk-free rate plus beta times the equity risk premium. Alternatives include the dividend growth model or a build-up method with size and company-specific premiums for small private firms.
How is WACC used in valuation?+
In a discounted cash flow model, free cash flows to the firm are discounted at WACC to estimate enterprise value. Projects with an expected return above WACC create value; those below destroy it.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.