Cost of equity is the return common shareholders require for bearing equity risk. In valuation, it is an estimated discount-rate input rather than an observable financing rate or a forecast of the stock’s future return.
The concept is closely related to the required return investors demand, but cost of equity applies specifically to equity capital and equity-level valuation.
How Cost of Equity Is Estimated
| Method | Formula or logic | Main boundary |
|---|---|---|
| CAPM | Risk-free rate + Beta × Equity risk premium | The estimate changes with the selected risk-free rate, beta, and equity risk premium. |
| Dividend growth model | D1 ÷ P0 + g | The method requires meaningful dividend and long-term growth assumptions and is not suitable for every company. |
The capital asset pricing model is widely used for market-based estimation because it connects the required equity return to the risk-free rate, beta, and the equity risk premium.
CAPM Formula and Worked Example
Cost of Equity = Risk-Free Rate + Beta × Equity Risk Premium
Assume a hypothetical company has a 4% risk-free rate, a beta of 1.2, and a 5% equity risk premium.
| Input | Assumption |
|---|---|
| Risk-free rate | 4.0% |
| Beta | 1.2 |
| Equity risk premium | 5.0% |
| Estimated cost of equity | 4.0% + (1.2 × 5.0%) = 10.0% |
The 10% result belongs to this assumption set. A change in the risk-free rate, beta, or equity risk premium changes the estimate even when the company’s operating forecasts remain unchanged.
Cost of Equity vs WACC
Cost of equity also feeds into the broader cost of capital, but the rate used in a valuation needs to match the cash-flow claim being valued.
Used for equity-level cash flows such as free cash flow to equity because those cash flows belong to shareholders.
Combines equity and debt financing costs and is used with firm-level cash flows such as free cash flow to the firm.
How Cost of Equity Affects Valuation
Holding the cash-flow forecast constant, a higher cost of equity applies heavier discounting to future equity cash flows and reduces their present value. A lower rate has the opposite effect.
The sensitivity becomes more important when a larger share of the estimated value depends on cash flows far into the future. The discount rate still has to be evaluated alongside the cash-flow assumptions rather than used to compensate for an unrealistic forecast.
Limits of the Estimate
CAPM depends on the risk-free rate, beta, and equity risk premium selected for the model. Dividend-based estimates depend on dividend and growth assumptions. Different defensible inputs can therefore produce different cost-of-equity estimates, and the resulting rate says nothing by itself about business quality or whether the current share price is attractive.