Weighted Average Cost of Capital (WACC) Formulas
Master WACC Formula
WACC = (We × Re) + (Wd × Rd × (1-T))
Cost of Equity (CAPM)
Re = Rf + β × (Rm - Rf)
After-Tax Debt Cost
Rd,after-tax = Rd × (1 - Tax Rate)
Step-by-Step Calculation Breakdown
Example: $1,000M Equity, $400M Debt, Rf = 4.25%, β = 1.10, ERP = 5.50%, Rd = 5.50%, T = 25%
1. Cost of Equity (CAPM): 4.25% + (1.10 × 5.50%) = 10.30%
2. After-Tax Cost of Debt: 5.50% × (1 - 0.25) = 4.125%
3. Total Capital (V): $1,000M + $400M = $1,400M
4. Weights: Equity = 71.43% ($1,000M ÷ $1,400M), Debt = 28.57% ($400M ÷ $1,400M)
5. Equity Contribution: 71.43% × 10.30% = 7.357%
6. Debt Contribution: 28.57% × 4.125% = 1.179%
7. Blended WACC: 7.357% + 1.179% = 8.536%
Corporate Hurdle Rate:8.54% Discount Rate
Applications in Valuation and Corporate Finance
- DCF Discount Rate (FCFF): In Discounted Cash Flow models, unlevered free cash flows are discounted at WACC because they belong to all capital claimants.
- Project Hurdle Rate (Capital Budgeting): For a capital expenditure or acquisition to create enterprise value, its Expected Internal Rate of Return (IRR) must strictly exceed WACC.
- Optimal Capital Structure: Management teams optimize leverage to minimize WACC, thereby maximizing the total enterprise value of the firm.