AI for WACC Calculation: Claude Tools for Weighted Average Cost of Capital

WACC and AI

Weighted Average Cost of Capital (WACC) is the most consequential single number in a DCF valuation — a 1% change in WACC can move implied equity value by 15-25%. Claude with ClaudeFinLab walks through every input: beta estimation (regression, Damodaran peer, Blume adjustment), equity risk premium, country risk premiums, cost of debt, capital structure, and the unlevering/relevering process.

Cost of Equity (CAPM)

• "Calculate the cost of equity using CAPM: Risk-free rate = 10-year US Treasury yield 4.35%. Equity risk premium = Damodaran implied ERP July 2026 = 4.8%. Levered beta = 1.24 (5-year monthly regression vs S&P 500). Cost of equity = Rf + β × ERP = 4.35% + 1.24 × 4.8% = 10.31%. Is this reasonable for a mid-cap industrial company?"
• "Apply size premium: the company is a $480M market cap small-cap. Using Duff & Phelps size premium for the micro-cap decile: +3.2%. Adjusted cost of equity = 10.31% + 3.2% = 13.51%. When should you add a size premium and when is it controversial?"
• "Company-specific risk adjustment: the company is a single-product company with 2 customers representing 65% of revenue. Add a company-specific risk premium of 2.0% for key-customer concentration. Total cost of equity = 13.51% + 2.0% = 15.51%. This is used in private company valuations — when is it appropriate?"

Beta Estimation

• "Estimate beta using peer group method (for a private company or division): Peer companies with their raw betas and D/E ratios: [Peer 1: β=1.42, D/E=0.45]; [Peer 2: β=1.18, D/E=0.28]; [Peer 3: β=1.55, D/E=0.62]; [Peer 4: β=1.31, D/E=0.38]. Tax rate 25%. Unlever each beta using Hamada: βu = βL / (1 + (1-T) × D/E). Compute median unlevered beta. Then re-lever using target D/E of 0.40."
• "Apply Blume beta adjustment: raw regression beta = 1.42. Blume-adjusted beta = 0.67 × 1.42 + 0.33 × 1.0 = 1.28. Rationale: raw betas drift toward 1.0 over time (mean reversion). Should I use the raw or adjusted beta, and why?"
• "Low-frequency beta for thinly-traded stock: the company trades $2M/day volume — its daily regression beta is unreliable due to non-synchronous trading. Use Dimson beta (sum of contemporaneous and lagged coefficients) or 4-week return interval instead of daily. How does this change the beta estimate?"

Equity Risk Premium (ERP)

• "Select the appropriate ERP: (1) Historical ERP arithmetic mean 1928-2025 = 6.4% (Damodaran). (2) Historical geometric mean = 4.6%. (3) Implied ERP (Damodaran, July 2026) = 4.8%. (4) Surveys: CFO survey ERP = 4.2%. Which should I use for a US company DCF and why? What's the practitioner consensus?"
• "Country risk premium for Brazil: Moody's rating Ba2. Brazil CDS spread = 185bps (5-year). Relative volatility of Brazil equity vs US equity = 1.35. CRP = Country CDS spread × (σEquity/σBond) = 185bps × 1.35 = 2.50%. Total ERP for Brazilian operations = US ERP 4.8% + CRP 2.5% = 7.3%."

Cost of Debt

• "Estimate pre-tax cost of debt: the company has $180M term loan at SOFR + 250bps. Current 3-month SOFR: 4.85%. Pre-tax cost of debt = 4.85% + 2.50% = 7.35%. After-tax cost of debt = 7.35% × (1 - 25%) = 5.51%. Alternatively, yield-to-maturity on publicly traded bonds if available."
• "Synthetic rating approach for a company without public debt: EBIT/interest expense (ICR) = $42M/$8.4M = 5.0x. Using Damodaran's synthetic rating table: ICR 4.5-6.0x → BBB rating → default spread ~1.8%. Cost of debt = risk-free rate 4.35% + 1.8% = 6.15%. After-tax = 6.15% × 0.75 = 4.61%."

Capital Structure and WACC Assembly

• "Assemble WACC: Equity market value $485M, debt (net) $180M, total capital $665M. Weights: E/V = 73%, D/V = 27%. Cost of equity 13.5%, after-tax cost of debt 5.51%. WACC = (73% × 13.5%) + (27% × 5.51%) = 9.86% + 1.49% = 11.35%. Should I use market value weights (standard) or book value weights (only for regulated utilities)?"
• "Target vs current capital structure: the company is currently 40% levered but plans to refinance to 25% debt over 3 years. Should WACC use current or target structure? Standard practice uses target structure as the terminal structure — but mid-year WACC is sometimes blended. Show the WACC at 40%, 25%, and the blended 3-year approach."
• "WACC sensitivity table: show WACC across beta (0.9, 1.0, 1.1, 1.2, 1.3) × ERP (4.0%, 4.5%, 5.0%, 5.5%, 6.0%) with risk-free rate fixed at 4.35% and capital structure fixed at 73%/27%. Which combination is the 'central case' and why?"

WACC in DCF Valuation

• "How does a 1% change in WACC affect DCF value? Base case: FCF Year 1-5 averaging $38M, terminal growth 2.5%, WACC 10.0% → implied EV $520M. WACC 9.0% → EV $610M (+17.3%). WACC 11.0% → EV $445M (-14.4%). This illustrates why WACC estimation deserves as much rigor as FCF projection."
• "APV (Adjusted Present Value) vs WACC: for a highly leveraged LBO where debt ratio changes significantly year by year, APV may be more appropriate. APV = Unlevered firm value + PV(tax shields). Show when to use WACC vs APV and compute both for this LBO with $180M debt declining to $60M over 5 years."

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