Cost of Equity
Executive Summary
Key Takeaways
- ✓ Cost of equity is the return equity investors require to hold a company's stock, given its systematic risk.
- ✓ The Capital Asset Pricing Model (CAPM) is the standard methodology used to estimate it.
- ✓ Cost of equity is one of two inputs blended into WACC, alongside the after-tax cost of debt.
- ✓ Cost of equity is used alone (not blended into WACC) as the discount rate for a levered free cash flow (FCFE) valuation.
- ✓ Cost of equity is always higher than the cost of debt for the same company, since equity holders bear residual risk after debt holders are paid.
Definition¶
Cost of equity is the rate of return equity investors require to compensate them for the risk of holding a company's stock. It reflects the company's systematic risk relative to the broader market and is a required input to both WACC and a direct FCFE-based valuation.
Estimation via CAPM¶
The standard methodology for estimating cost of equity is the Capital Asset Pricing Model (CAPM):
Cost of Equity = Risk-free Rate + Beta × Equity Risk Premium
See the CAPM glossary page for the full breakdown of each input (risk-free rate, beta estimation including unlevering/relevering, and the equity risk premium).
Two Roles in a DCF¶
As a component of WACC. Cost of equity is blended with the after-tax cost of debt, weighted by the target capital structure, to produce WACC — the discount rate used with FCFF to produce enterprise value.
As a standalone discount rate. When a valuation uses FCFE (levered free cash flow, already net of debt service), cost of equity is used alone — not blended with the cost of debt — since the cash flow itself already reflects the effect of financing. Discounting FCFE at cost of equity produces equity value directly.
Why Cost of Equity Exceeds Cost of Debt¶
Equity holders hold a residual claim: they are paid after debt holders, and their return is not contractually fixed. This subordination and variability of return requires a higher expected return than debt, which carries a contractual interest rate and priority claim on assets and cash flows. This relationship holds for essentially every company and is a basic sanity check on a WACC or cost of equity build — cost of equity below cost of debt indicates an error in the underlying inputs.
Audit Considerations¶
- Confirm the CAPM inputs (risk-free rate, beta, ERP) are sourced, dated, and disclosed
- Confirm cost of equity exceeds cost of debt for the same company as a basic sanity check
- Confirm cost of equity is applied consistently — either blended into WACC for an FCFF valuation, or used alone for an FCFE valuation, and not both simultaneously
- Where country or size premia are added, confirm they are separately disclosed rather than folded silently into the beta or ERP figure
Common Errors¶
| Error | Description | Risk |
|---|---|---|
| Cost of equity below cost of debt | CAPM inputs produce an equity return lower than the debt rate | Signals an input error — this relationship should not hold for a normally structured company |
| Double-applying cost of equity | Used both to build WACC and again alone against FCFE in the same model | Produces internally inconsistent, incomparable valuation outputs |
| Undocumented risk premia | Country or size premium added without disclosure | Cost of equity cannot be independently assessed |
Continue Reading¶
Prerequisites¶
- Discounted Cash Flow (DCF) Valuation — the parent pillar
- CAPM (Capital Asset Pricing Model)
Related Glossary¶
How OXXON tests thisRun a free structural check with FMAE
Frequently Asked Questions
How is cost of equity calculated?
Most commonly using CAPM, cost of equity = risk-free rate + beta × equity risk premium. Some practitioners layer on additional premia for country risk or company size.
Why is cost of equity always higher than cost of debt?
Because equity holders have a residual claim on a company's cash flows and assets, paid only after debt holders, and bear the risk of business underperformance without a fixed contractual payment. This higher risk requires a correspondingly higher expected return.
When is cost of equity used directly rather than blended into WACC?
When valuing a levered free cash flow (FCFE), which already reflects the effect of debt service, cost of equity is used alone as the discount rate, producing equity value directly.
Does cost of equity change if a company's leverage changes?
Yes. Higher leverage generally increases both the volatility of equity returns (raising beta) and financial risk, increasing the cost of equity. This relationship is formalized through beta relevering (see CAPM and the Hamada equation).
Related Articles
CAPM (Capital Asset Pricing Model)
The Capital Asset Pricing Model (CAPM) is the standard methodology for estimating the cost of equity — the return equity investors require to hold a company's stock, given its systematic risk relative to the broader market. CAPM expresses cost of equity as the risk-free rate plus the company's beta multiplied by the equity risk premium (the excess return the market as a whole is expected to earn over the risk-free rate). CAPM is the most widely used cost-of-equity methodology in institutional valuation practice and is the standard input to the cost-of-equity component of WACC.
Cost of Debt
Cost of debt is the effective interest rate a company pays on its borrowings, reflecting its credit risk and the terms available in current debt markets. In a WACC build, cost of debt is used on an after-tax basis, since interest expense is tax-deductible in most jurisdictions and the resulting tax shield reduces the effective cost of borrowing to the company. Cost of debt can be measured on a marginal basis (the rate at which new debt could currently be raised) or an embedded basis (the weighted average rate on debt already outstanding), and the choice between them should match the analytical purpose.
WACC (Weighted Average Cost of Capital)
WACC (Weighted Average Cost of Capital) is the rate of return that a company must earn on its existing assets to maintain the value of its equity and satisfy both its debt holders and equity investors. It is calculated as the weighted average of the after-tax cost of debt and the cost of equity, with the weights determined by the proportion of each in the total capital structure. WACC is used primarily as the discount rate in a discounted cash flow (DCF) valuation, where it converts projected free cash flows into present value. It is also used as a return hurdle: a project or investment is value-creating if its expected return exceeds the WACC.
FCFE (Levered Free Cash Flow)
FCFE (Free Cash Flow to Equity), also called levered free cash flow, is the cash remaining for equity holders after a business has met its operating needs, capital expenditure, working capital investment, and all debt service obligations — interest and principal repayment (net of new borrowing). Because FCFE already reflects the effect of the company's actual capital structure, it is discounted at the cost of equity rather than WACC, and the resulting present value is equity value directly, with no further enterprise-to-equity bridge required.
Discounted Cash Flow (DCF) Valuation
Discounted cash flow (DCF) valuation values a business, project, or asset as the present value of the cash flows it is expected to generate in the future. It is the most theoretically grounded of the major valuation methodologies, resting directly on the principle that a dollar of cash flow is worth more today than the same dollar received in the future, and that value is created when future cash flows exceed what capital providers require as compensation for the time value of money and risk. This page is the hub for the Knowledge Centre's DCF content: what DCF is and why it works, how free cash flow and discount rates are built, how terminal value is calculated and stress-tested, the method variants practitioners choose between, and — distinctively — how DCF failure modes map onto FMAE's existing structural audit rule taxonomy, since no generic valuation resource ties DCF mechanics to a named, testable audit standard.