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ValuationWACC

What is WACC (Weighted Average Cost of Capital)?

WACC is the blended rate of return that a company must earn on its assets to satisfy both equity holders and debt holders. It is the discount rate used in DCF models and the hurdle rate against which ROIC is compared. A business that earns ROIC above its WACC creates value; below WACC, it destroys value.

Formula

WACC = (E/V x Ke) + (D/V x Kd x (1 - Tax Rate)) where E = equity value, D = debt value, V = E + D, Ke = cost of equity, Kd = cost of debt

Why WACC Is the Most Sensitive DCF Input

In a DCF model, every projected future cash flow is divided by (1 + WACC)^n. Because this discounting compounds over many years, small changes in WACC produce outsized swings in intrinsic value. A company with $100 of terminal value discounted over 10 years at 8% WACC is worth ~$46 today; at 10% WACC it falls to ~$39 -- a 15% difference from a 2% WACC change. This mathematical sensitivity means analysts must justify their WACC assumptions rigorously, and should always present a range of WACC assumptions in a sensitivity table.

The tax shield on debt is a key reason companies have an optimal capital structure. Interest payments are tax-deductible, so a company paying 6% on debt effectively pays only 6% x (1 - 25%) = 4.5% after-tax. This makes debt cheaper than equity and lowers the WACC up to a point. Beyond that point, additional leverage raises financial distress risk, pushing up both the cost of debt and the equity risk premium, ultimately increasing WACC rather than reducing it.

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Enter equity weight, debt weight, cost of equity (CAPM), cost of debt, and tax rate to compute WACC instantly. Use it as the discount rate in your DCF analysis.

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Frequently Asked Questions

What is WACC and how is it used in DCF valuation?+
WACC is the discount rate applied to a company's projected free cash flows in a DCF model. It represents the blended opportunity cost of capital -- what investors could earn on an alternative investment of equivalent risk. Because of the time value of money, future cash flows are worth less than present cash flows; WACC is the rate at which those future flows are discounted back to today. A 1% change in WACC can alter the DCF intrinsic value estimate by 10-25% depending on the growth assumptions, which is why WACC is the most sensitive input in any DCF model.
How is the cost of equity calculated in WACC?+
Cost of equity (Ke) is typically estimated using the Capital Asset Pricing Model (CAPM): Ke = Risk-Free Rate + Beta x Equity Risk Premium. The risk-free rate is usually the 10-year US Treasury yield (approximately 4-5% in current conditions). Beta measures the stock's sensitivity to market moves. The Equity Risk Premium (ERP) is the expected excess return of equities over the risk-free rate, typically estimated at 5-6% historically. For a stock with beta of 1.0: Ke = 4.5% + 1.0 x 5.5% = 10%. Higher-beta growth stocks will have higher Ke and higher WACC.
Why does WACC differ across industries?+
WACC varies because each industry has a different mix of risk, capital structure, and financing costs. Capital-intensive, low-risk utilities have WACC of 5-8%: regulated cash flows support high debt loads (cheap cost of debt), low beta (low cost of equity). Stable consumer staples: 7-9%. Diversified industrials: 8-11%. Growth technology: 10-14%, driven by high equity risk and typically minimal debt. Unprofitable early-stage startups: 15-25% or higher, because the elevated risk of cash flows far in the future demands a high discount rate. Using the wrong WACC for an industry will systematically over- or under-value the business.
What is the relationship between WACC and ROIC?+
ROIC minus WACC equals Economic Value Added per unit of capital. When ROIC > WACC, the company earns more on its invested capital than its capital costs, creating economic profit and building intrinsic value above book value. When ROIC = WACC, the business is breaking even on an economic basis -- it earns its cost of capital but creates no excess value. When ROIC < WACC, the business destroys value even if it is accounting-profitable, because it earns less than what shareholders and lenders require. The ROIC/WACC spread, sustained over many years, is one of the most reliable predictors of long-term stock returns.

Related Terms

ROIC

After-tax operating profit on all invested capital

Discount Rate

Rate used to convert future cash to present value

Equity Risk Premium

Extra return required above the risk-free rate

Net Present Value

Discounted value of future cash flows

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