WACC Calculator
Calculate a company's Weighted Average Cost of Capital (WACC) by entering the market value of equity and debt, cost of equity, cost of debt, and corporate tax rate. WACC represents the minimum return a company must earn to satisfy its investors.
The Weighted Average Cost of Capital (WACC) represents the average rate a company pays to finance its operations through a mix of equity and debt. It's the discount rate used in DCF valuations to translate future cash flows into present value, and it serves as the hurdle rate for evaluating new projects — investments returning above WACC create shareholder value; those below WACC destroy it.
The calculation weights the cost of each capital source by its proportion of total financing. For a company with $5M of equity at 10% cost and $2M of debt at 5% cost (after tax adjustment), the WACC blends them: equity contributes 71% of the weight (5/7 of capital structure), debt contributes 29%. The result accounts for the fact that debt is typically cheaper than equity (debt holders take less risk, accept lower returns) AND that interest payments are tax-deductible (creating a "tax shield" that reduces the effective cost of debt).
This calculator computes WACC from market values of equity and debt, costs of each, and the corporate tax rate. Use it for: DCF valuation (where WACC is the discount rate), capital structure analysis (how would WACC change if the company added more debt?), project evaluation (is the project's expected IRR above WACC?), and corporate finance education. WACC is one of the foundational concepts in corporate finance and a critical input for any rigorous business valuation.
Inputs
Results
WACC
8.27%
Equity Weight
71.4%
Debt Weight
28.6%
After-Tax Cost of Debt
3.95%
Capital Structure
WACC Components
Formula
How to use this calculator
- Enter the market value of equity (stock price × shares outstanding for public companies; estimated valuation for private companies).
- Enter the market value of debt (bonds, term loans, notes — at market value, not book value if they differ).
- Enter the cost of equity. Use the Capital Asset Pricing Model (Rf + β × equity risk premium) or industry benchmarks. Typical range: 8-15% for U.S. public companies.
- Enter the cost of debt (pre-tax). Use the yield on the company's bonds or the rate it would pay on new debt at similar credit quality.
- Enter the corporate tax rate. U.S. federal: 21%. Add state corporate tax (averages ~5%) for combined rate of ~26%.
- Review the calculated WACC. Use it as: (1) discount rate in DCF analysis, (2) hurdle rate for new project evaluation, (3) baseline for comparing returns on different investments.
- For private companies, WACC is harder to calculate precisely (no market value of equity, often opaque debt market). Use industry averages for similar public companies as a starting point.
- For sensitivity analysis, recalculate at different capital structures (more debt, less debt) to see how WACC changes. Optimal capital structure typically minimizes WACC, though too much debt eventually raises both cost of equity and cost of debt due to financial distress risk.
Worked examples
Mature large-cap company
Apple-like profile: $3.5T equity, $100B debt, 9% cost of equity, 4% cost of debt, 26% effective tax rate. Total: $3.6T Equity weight: 97.2% Debt weight: 2.8% After-tax cost of debt: 4% × 0.74 = 2.96% WACC = (0.972 × 9%) + (0.028 × 2.96%) = 8.75% + 0.08% = 8.83% Very debt-light companies have WACC nearly equal to cost of equity. Most large U.S. tech companies operate this way — substantial cash piles, modest debt, WACC dominated by equity cost.
Highly leveraged company
Industrial company: $300M equity, $700M debt, 12% cost of equity (higher due to leverage), 6% cost of debt, 26% tax rate. Total: $1B Equity weight: 30% Debt weight: 70% After-tax cost of debt: 6% × 0.74 = 4.44% WACC = (0.30 × 12%) + (0.70 × 4.44%) = 3.60% + 3.11% = 6.71% Higher leverage produces lower WACC at this profile — but increases financial risk. Recessions, interest rate spikes, or earnings volatility can be catastrophic for high-leverage companies. The "optimal capital structure" balances WACC reduction against financial distress risk.
Small private company
Small business: $5M equity, $2M debt, 15% cost of equity (small company premium), 7% cost of debt (bank loan), 25% combined tax rate. Total: $7M Equity weight: 71.4% Debt weight: 28.6% After-tax cost of debt: 7% × 0.75 = 5.25% WACC = (0.714 × 15%) + (0.286 × 5.25%) = 10.71% + 1.50% = 12.21% Smaller, riskier companies have higher WACC across the board — higher cost of equity (compensating for small-company premium and illiquidity), higher cost of debt (less favorable terms), and limited debt capacity. Hurdle rate for new projects is meaningfully higher than for large public companies.
When to use this calculator
Use this calculator when performing DCF valuation, evaluating new capital projects, analyzing capital structure decisions, or learning corporate finance fundamentals.
Pair with: DCF calculator (WACC is the discount rate), NPV calculator (WACC is the hurdle rate), IRR calculator (compare to WACC to judge project value), and CAGR calculator (for evaluating actual returns vs. expected based on WACC).
Important practical realities:
1. **Cost of equity is hard to estimate.** CAPM is the textbook approach but produces wide ranges depending on inputs (which beta period to use, which risk-free rate, which equity premium). Most analysts use ranges (e.g., 8-12%) rather than precise point estimates.
2. **Market value matters.** Use market value of equity (stock price × shares) and market value of debt (if different from book — for distressed credits, debt trades below book). Book values can mislead.
3. **WACC changes over time.** Capital structure shifts, market conditions change interest rates, and risk profiles evolve. Re-estimate WACC periodically (especially when using it for ongoing project hurdle rates).
4. **Industry context matters.** Average WACC by industry varies: utilities 5-8%, mature tech 8-10%, biotech 12-18%, distressed companies 15%+. Compare to industry peers, not absolute thresholds.
5. **WACC is a hurdle, not a target return.** Projects should earn meaningfully ABOVE WACC to create value. Projects with IRR exactly equal to WACC are NPV-neutral, not value-creating.
Common mistakes to avoid
- Using book values instead of market values. Market value of equity (stock price × shares) and market value of debt are correct. Book values can be significantly different.
- Forgetting the tax shield on debt. Pre-tax cost of debt overstates the true cost — interest is deductible, so effective cost is Rd × (1 − tax rate).
- Using personal opportunity cost as cost of equity. WACC is the company's cost of capital, calibrated to what shareholders require. Personal alternatives differ.
- Assuming optimal capital structure is "lots of debt." High leverage reduces WACC mathematically but increases financial distress risk, which raises both cost of equity and cost of debt eventually. Optimal is typically moderate.
- Using WACC as discount rate for project with different risk than the company's average. A risky new venture from a low-risk utility should use a higher discount rate than the utility's WACC.
- Forgetting that WACC changes. Re-estimate periodically, especially after major capital structure shifts (large debt issuance, share buybacks, equity raises) or rate environment changes.
Frequently Asked Questions
Sources & further reading
- Cost of Capital — Investor Education — U.S. Securities and Exchange Commission
- Corporate Finance Fundamentals — Financial Industry Regulatory Authority
- Federal Reserve Economic Data (FRED) — interest rates — Federal Reserve Bank of St. Louis