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WACC: The Weighted Average Cost of Capital, Explained
The weighted average cost of capital (WACC) is the blended rate a company pays to fund its assets, weighting the after-tax cost of debt and the cost of equity by how much of each sits in the capital structure at market value. It is the single number analysts use to discount a business’s future cash flows to present value. A typical U.S. large-cap WACC in 2026 lands roughly between 7% and 10%.
WACC answers one question: what return does a company have to earn on its assets just to satisfy every investor who funded them? Lenders want interest. Shareholders want a return that compensates them for risk. Blend those two costs by their weights and you get the minimum acceptable return, the rate below which the business destroys value.
The WACC formula
WACC blends two funding costs, each weighted by its share of total capital, with a tax adjustment applied only to debt. The formula is:
WACC = (E/V x Re) + (D/V x Rd x (1 – Tc))
Where E is the market value of equity, D is the market value of debt, V is E + D (total capital), Re is the cost of equity, Rd is the pre-tax cost of debt, and Tc is the marginal corporate tax rate (21% U.S. federal in 2026, higher once state tax is added).
Each term reads simply. E/V and D/V are the weights, and they must sum to 1. Re and Rd are the costs of each source. The (1 – Tc) piece shrinks the debt cost because interest is tax-deductible. If a company also has preferred stock, add a third term: P/V x Rp, where P is the market value of preferred and Rp is its cost.
Weights should use market values, not book values. Book equity on the balance sheet can be a fraction of market capitalization, and using it can badly distort the answer. For a public company, market equity is share price times shares outstanding.
| Component | Symbol | How it is measured |
|---|---|---|
| Cost of equity | Re | CAPM: Rf + Beta x equity risk premium |
| Pre-tax cost of debt | Rd | Yield on the company’s debt, or interest expense / total debt |
| Tax adjustment | (1 – Tc) | 1 minus the marginal tax rate (federal 21% plus state) |
| Equity weight | E/V | Market value of equity / total capital |
| Debt weight | D/V | Market value of debt / total capital |
Cost of equity: the CAPM approach
The cost of equity is the return shareholders require for holding the stock, and most analysts estimate it with the Capital Asset Pricing Model (CAPM). The formula is Re = Rf + Beta x (Rm – Rf), where Rf is the risk-free rate, Beta measures how volatile the stock is versus the market, and (Rm – Rf) is the equity risk premium.
The risk-free rate is usually the yield on the 10-year U.S. Treasury, often around 4% to 4.5% in 2026. Beta reflects sensitivity to market moves: a beta of 1.0 moves with the market, above 1.0 amplifies it, and below 1.0 dampens it. The equity risk premium, the extra return investors demand for stocks over Treasuries, commonly sits near 4.5% to 5.5% in U.S. practice.
Cost of equity is almost always higher than cost of debt. Shareholders sit last in line if the company fails, so they demand more. A stock with a risk-free rate of 4.2%, a beta of 1.1, and a 5% equity risk premium has a cost of equity of 4.2% + 1.1 x 5% = 9.7%.
After-tax cost of debt
The after-tax cost of debt is the interest rate a company pays on borrowing, reduced by the tax savings that interest creates. Because interest expense is deductible, each dollar of interest lowers taxable income, so the real economic cost is Rd x (1 – Tc). This tax break is called the interest tax shield.
Start with the pre-tax cost of debt: the yield the company would pay to borrow today, which you can approximate from the yield on its outstanding bonds or from interest expense divided by total debt. Then apply the tax shield. A firm borrowing at 6% with a 21% federal rate has an after-tax cost of debt of 6% x (1 – 0.21) = 4.74%.
The tax adjustment applies only to debt, never to equity, because dividends are paid from after-tax profit and are not deductible. State corporate income tax can push the combined marginal rate above 21%, which deepens the shield. A company’s effective rate may differ from its marginal rate, and analysts generally use the marginal rate here because WACC looks forward to the next dollar borrowed.
Using WACC as a DCF discount rate
In a discounted cash flow (DCF) valuation, WACC is the rate that converts a company’s projected future cash flows into today’s dollars. When you value the whole firm using unlevered free cash flow (cash available to both lenders and shareholders), WACC is the correct discount rate because it reflects the return required by all capital providers.
The logic is that money has a time cost and a risk cost, and WACC captures both. A cash flow of $1 million expected in five years, discounted at a 9% WACC, is worth about $650,000 today. Raise the WACC and present value falls; lower it and present value rises. This is why small changes in the assumed cost of capital swing valuations so much.
WACC also serves as a hurdle rate in capital budgeting. A project should clear the bar only if its internal rate of return (IRR) meets or beats WACC, since a return below the cost of capital erodes value. Many firms add a risk premium for riskier projects: a 9% WACC plus a 2% project premium sets an 11% hurdle. For deeper valuation context, see how the same discounting logic flows through the cash flow statement and how analysts read profitability in an income statement.
Worked example: computing WACC end to end
Consider Meridian Corp, a public company with these inputs. Equity market value is $800 million and debt market value is $200 million, so total capital V is $1 billion. That gives an equity weight of 80% and a debt weight of 20%.
Cost of equity by CAPM: risk-free rate 4.2%, beta 1.1, equity risk premium 5.0%. Re = 4.2% + 1.1 x 5.0% = 9.7%. Pre-tax cost of debt is 6.0%, and the marginal tax rate is 21%, so the after-tax cost of debt is 6.0% x (1 – 0.21) = 4.74%.
| Step | Calculation | Result |
|---|---|---|
| Equity weight (E/V) | 800 / 1,000 | 80% |
| Debt weight (D/V) | 200 / 1,000 | 20% |
| Cost of equity (Re) | 4.2% + 1.1 x 5.0% | 9.70% |
| After-tax cost of debt | 6.0% x (1 – 0.21) | 4.74% |
| Equity contribution | 0.80 x 9.70% | 7.76% |
| Debt contribution | 0.20 x 4.74% | 0.95% |
| WACC | 7.76% + 0.95% | 8.71% |
Meridian’s WACC is about 8.7%. That is the rate its analysts would use to discount unlevered free cash flow in a DCF, and the minimum return any new project should clear before it adds value.
What counts as a good WACC
There is no universal “good” WACC, because the number reflects a company’s risk and capital mix, not its quality. A low WACC signals cheap capital, often a stable, low-risk firm. A high WACC signals that investors demand more, usually because the business or its debt load is riskier. Compare a company’s WACC to its return on invested capital, not to a fixed target.
Value is created when returns exceed the cost of capital. A firm earning 15% on invested capital against a 9% WACC creates six cents of value per dollar invested. A firm earning 7% against that same 9% WACC destroys value even while reporting a profit. This gap, not the WACC alone, is what matters. Related margin and return metrics like return on equity and gearing measures like the debt-to-equity ratio help explain why one company’s WACC differs from another’s.
Frequently asked questions
What is WACC in simple terms?
WACC is the average rate a company pays to fund itself, blending the cost of borrowing (debt) and the return shareholders expect (equity), weighted by how much of each it uses. It represents the minimum return the business must earn on its assets to keep every investor satisfied. A return below WACC means the company is losing value on the capital it deploys.
Why is the cost of debt multiplied by (1 – tax rate)?
Interest on debt is tax-deductible, so borrowing reduces a company’s taxable income and its tax bill. The (1 – tax rate) factor captures that saving, called the interest tax shield. At a 21% federal rate, a 6% borrowing cost has a true after-tax cost of 4.74%. Equity gets no such adjustment because dividends are paid from after-tax profit and are not deductible.
Should WACC use book values or market values?
WACC weights should use market values of debt and equity, not book values from the balance sheet. Book equity can be far below market capitalization, which would understate the equity weight and distort the result. Market equity is share price times shares outstanding. For debt, market value is often close to book value unless interest rates have moved sharply since issuance.
How is WACC used in a DCF valuation?
In a DCF, WACC is the discount rate applied to unlevered free cash flow to convert future cash into present value. It is the right rate because unlevered cash flow belongs to both lenders and shareholders, and WACC reflects the return both groups require. A higher WACC lowers the present value and the resulting valuation; a lower WACC raises it.
Is WACC the same as the hurdle rate?
WACC is often used as the baseline hurdle rate, the minimum return a project must clear, but the two are not always identical. Companies frequently add a risk premium to WACC for projects riskier than the firm’s average, so a 9% WACC might become an 11% hurdle. Using one company-wide WACC for every project can lead to overinvesting in risky projects and underinvesting in safe ones.
What is a typical WACC for a U.S. company?
Most U.S. large-cap companies show a WACC roughly between 7% and 10% in 2026, though it varies widely by industry and risk. Stable utilities and consumer staples tend toward the low end because their cash flows are predictable and their betas are low. Early-stage or highly cyclical firms can run well above 10% because investors demand more for the added risk.
Reviewed by The Ledgerism Editorial Team. Last reviewed: July 2026.