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CAPM Calculator (Cost of Equity)
In short: the capital asset pricing model (CAPM) estimates the cost of equity, the return investors require for a stock’s systematic risk, as the risk-free rate plus beta times the market risk premium. This calculator computes it from your inputs, lets you enter the premium directly or derive it from an expected market return, adds an optional country risk premium, and plots the security market line.
The CAPM formula
Ke = Rf + β × (Rm − Rf), where Ke is the cost of equity, Rf the risk-free rate, β the beta, and (Rm − Rf) the market risk premium.
The capital asset pricing model, universally abbreviated CAPM, answers one of the most important questions in finance: what return should an investor require for holding a risky asset? Its answer is elegant and has shaped decades of practice. Investors should be rewarded not for all risk, but only for the risk they cannot diversify away, and that risk is measured by beta.
The required return, which for a company is its cost of equity, equals the risk-free rate plus beta times the market risk premium. This calculator applies that model to your inputs, the risk-free rate, beta, and the market risk premium, and returns the cost of equity along with the risk premium it embeds and the security market line that places your asset in relation to the market.
You can enter the market risk premium directly or derive it from an expected market return, and you can add an optional country risk premium for emerging-market analysis.
Because the cost of equity is the single hardest input in a weighted average cost of capital, and because valuations are so sensitive to it, getting the CAPM right is one of the foundational skills of corporate finance, and this tool is built to make the calculation transparent, from the inputs through to the line on the chart.
What the CAPM means
The insight at the heart of the CAPM is that risk comes in two kinds, and only one of them deserves a reward. Some risk is specific to a single company, its management, its products, a lawsuit, and this risk can be diversified away by holding many different assets, so a well-diversified investor is not exposed to it and should not be paid for it.
The other kind is market risk, the risk that comes from the whole economy rising and falling, and this cannot be diversified away because it affects everything at once. The CAPM says investors are compensated only for this undiversifiable market risk, and that an asset exposure to it is captured by beta. The required return therefore starts at the risk-free rate, the return available with no risk at all, and adds a premium proportional to how much market risk the asset carries.
This is why two assets with the same total volatility can have very different required returns: what matters is not total risk but the part that moves with the market.
The CAPM formula
The formula is compact: the cost of equity equals the risk-free rate plus beta multiplied by the market risk premium, and the market risk premium is the expected return on the market minus the risk-free rate. In symbols, Ke = Rf + β × (Rm − Rf). Each piece has a clear meaning. The risk-free rate Rf is the baseline return with no risk, usually the yield on a government bond. Beta β scales the market risk premium up or down according to how sensitive the asset is to the market.
And the market risk premium (Rm − Rf) is the reward the market as a whole offers over the risk-free rate. Working an example, with a risk-free rate of four percent, a beta of 1.2, and a market risk premium of five percent, the cost of equity is four percent plus 1.2 times five percent, which comes to ten percent.
The calculator performs exactly this arithmetic, and it lets you supply the market risk premium directly, or supply an expected market return from which it derives the premium by subtracting the risk-free rate.
Understanding beta
Beta is the CAPM measure of systematic risk, and it is the input that most directly shapes the cost of equity. It expresses how much an asset return tends to move when the market moves. A beta of one means the asset moves one-for-one with the market, so it carries average market risk and earns the average market return.
A beta of 1.5 means the asset tends to move one and a half times as much as the market, up and down, so it is aggressive and its owners demand a higher return to bear the extra swings. A beta of 0.6 means the asset moves less than the market, a defensive profile that comes with a lower required return. Beta can even be negative, an unusual case in which the asset tends to move opposite the market, making it valuable as a hedge and giving it a required return below the risk-free rate.
Beta is typically estimated by regressing historical asset returns on market returns, or looked up from a data provider, and because it is an estimate it is always worth testing across a range.
The market risk premium
The market risk premium is the extra return investors expect for holding the whole stock market rather than a risk-free asset, and it is the engine that turns beta into a premium. It equals the expected market return minus the risk-free rate. In developed markets the premium has historically averaged somewhere in the region of four to six percent, but it is genuinely uncertain and much debated, and the figure you choose has a large effect on the answer, because it is multiplied by beta.
There are several ways to estimate it: from the long-run history of market returns above the risk-free rate, from forward-looking models built on current prices and expected dividends or earnings, or by adopting a published consensus figure.
This calculator accommodates both habits: if you have a direct view on the premium you can enter it, and if you would rather think in terms of the return you expect from the market you can enter that and let the tool subtract the risk-free rate to obtain the premium.
The risk-free rate
The risk-free rate anchors the whole model, and it appears in two places at once: as the base of the cost of equity and inside the market risk premium. It represents the return on an asset with no default risk, proxied in practice by the yield on high-quality government debt.
In the United States the ten-year Treasury yield is a common choice; in Mexico or Brazil the corresponding government bond serves the same role; and the maturity should broadly match the horizon of the investment being analysed, so that a long-lived business is discounted with a long-term rate. No asset is perfectly risk-free, but sovereign debt of a strong issuer is the accepted stand-in.
Because the risk-free rate feeds the cost of equity directly and also through the premium, movements in interest rates pass straight through the CAPM: when rates rise, costs of equity rise and valuations fall, and when rates fall, the reverse occurs, which is one reason equity markets are so sensitive to central-bank policy.
The security market line
The CAPM has a natural picture, the security market line. Plot required return on the vertical axis and beta on the horizontal, and the model traces a straight line: it begins at the risk-free rate where beta is zero, since an asset with no market risk earns only the risk-free rate, and it rises with a slope equal to the market risk premium, so that at a beta of one the required return equals the expected market return.
Every correctly priced asset lies on this line, its required return set by its beta and nothing else. The line is a diagnostic as well as a definition. An asset that plots above the line is expected to return more than the CAPM requires for its risk, which makes it attractive or underpriced, while one that plots below offers too little return for its risk and is unattractive or overpriced.
This calculator draws the security market line for your risk-free rate and premium and marks your asset on it, so you can see immediately where its required return sits relative to its risk and to the market.
How CAPM feeds the cost of capital
The most important practical use of the CAPM is to estimate the cost of equity, which is one of the two main ingredients of a company weighted average cost of capital. WACC blends the cost of equity with the after-tax cost of debt in proportion to how much of each the company uses. The cost of debt is comparatively easy to observe, since it is the interest rate on the company borrowings adjusted for tax; the cost of equity is not observable and must be estimated, and the CAPM is the standard method.
The workflow is therefore sequential: estimate the cost of equity here, then carry it into the WACC calculation as the cost-of-equity input. This is why the CAPM and WACC tools in this silo are designed as a pair, and why the WACC page points back to this one for its equity input.
Because the cost of equity is usually the largest and most uncertain component of the WACC, the care you take with the CAPM flows directly into the reliability of every valuation and investment decision that rests on the WACC.
Country risk and emerging markets
The standard CAPM was developed with mature capital markets in mind, and applied unchanged to a company in a higher-risk economy it will understate the return investors actually demand. Investing in an emerging market such as Mexico or Brazil carries additional political, economic, and currency risk that the domestic risk-free rate and beta do not fully capture.
The common remedy is to add a country risk premium to the cost of equity, producing an emerging-market version of the CAPM in which the cost of equity equals the risk-free rate plus beta times the market risk premium plus the country risk premium. The country premium is often estimated from the spread between the country sovereign bonds and a benchmark such as United States Treasuries, sometimes scaled up to reflect the greater volatility of equities relative to bonds.
This calculator provides an optional country-risk-premium field: leave it at zero for a developed-market estimate, or enter a premium to reflect the specific risk of the market you are analysing, which is a meaningful refinement for Latin American and other emerging-market work.
Five worked examples from the market
Example 1: a baseline stock
Risk-free rate 4%, beta 1.2, market risk premium 5%. Ke = 4% + 1.2 × 5% = 4% + 6% = 10%. The stock’s above-average beta lifts its cost of equity two points over the market.
Example 2: a defensive stock
Same market, but beta 0.6. Ke = 4% + 0.6 × 5% = 4% + 3% = 7%. A low-beta, defensive business carries a cost of equity below the market return because it moves less than the market.
Example 3: an aggressive, high-beta stock
Beta 1.6 in the same market. Ke = 4% + 1.6 × 5% = 4% + 8% = 12%. The high beta amplifies the market premium, so investors demand a much higher return.
Example 4: deriving the premium from the market return
Risk-free rate 4%, beta 1.2, expected market return 9%. The market risk premium is 9% − 4% = 5%, so Ke = 4% + 1.2 × 5% = 10% — the same result as Example 1, reached from the expected market return.
Example 5: an emerging-market company
Take Example 1 and add a country risk premium of 3% for an emerging market. Ke = 4% + 1.2 × 5% + 3% = 13%. The country premium raises the required return for the added political and currency risk.
Three expert tips for a sound cost of equity
Match the risk-free rate to the horizon
Use a government-bond yield whose maturity matches the life of the cash flows — typically a 10-year rate for a long-lived business, not a short-term rate.
Do not add company-specific risk
CAPM prices only systematic, non-diversifiable risk through beta. Adding a premium for company-specific risk double-counts risk the model deliberately excludes; only a country premium for emerging markets is a standard addition.
Treat beta as an estimate and test a range
Beta comes from historical data and is uncertain, so re-lever comparable-company betas to your capital structure where needed and run the cost of equity across a range rather than trusting a single number.
How each input moves the cost of equity
Because the CAPM is a simple linear formula, it is easy to see how each input moves the answer, and knowing this helps you focus estimation effort. A higher risk-free rate raises the cost of equity almost one-for-one, because it lifts the base and, if you hold the expected market return fixed, it also narrows the premium; in most practical uses where the premium is held constant, the risk-free rate passes through directly.
A higher beta raises the cost of equity in proportion to the market risk premium, so beta matters most when the premium is large. A higher market risk premium raises the cost of equity in proportion to beta, so it matters most for high-beta assets. And an added country risk premium raises the cost of equity point-for-point. The upshot is that for a typical company with a beta near one, the cost of equity is roughly as sensitive to the risk-free rate and the premium as to beta, while for aggressive high-beta companies beta and the premium dominate.
Testing a range on each input, which the calculator makes quick, reveals where the uncertainty in your estimate really lies.
CAPM versus other cost-of-equity methods
The CAPM is the most widely used method for the cost of equity, but it is not the only one, and knowing the alternatives clarifies its place. The dividend discount model, or Gordon growth model, estimates the cost of equity from a company current dividend, its share price, and an assumed dividend growth rate; it is intuitive for stable, dividend-paying companies but breaks down for firms that pay no dividends or whose growth is hard to forecast.
The bond-yield-plus-risk-premium approach adds a judgmental equity premium to the company own cost of debt, a rough but quick check. Multi-factor models such as the Fama-French three-factor and later extensions augment the CAPM with additional factors, notably company size and value characteristics, that empirical research found to explain returns the single market factor misses; they can be more accurate but require more data and estimation.
The CAPM endures as the default because it is simple, transparent, grounded in a clear theory of diversifiable versus systematic risk, and adequate for most purposes; the alternatives are best seen as complements or cross-checks rather than replacements.
Common mistakes to avoid
Several errors recur when people apply the CAPM. The first is using a mismatched risk-free rate, such as a short-term rate to value a long-lived business; match the maturity to the horizon. The second is double-counting risk by adding a company-specific risk premium on top of the CAPM when that risk is diversifiable and therefore already excluded by the model deliberately; only non-diversifiable risk belongs.
The third is using a stale or ill-fitting beta, for instance a raw historical beta for a company whose capital structure or business has changed; consider adjusting or re-levering beta. The fourth is treating the market risk premium as precisely known when it is genuinely uncertain; test a range. The fifth is forgetting country risk when analysing an emerging market, which understates the required return. And the sixth is confusing the cost of equity with the WACC: the CAPM gives the cost of equity alone, which is only one input to the WACC.
The calculator handles the arithmetic, but these judgments about inputs are yours, and they are where most of the real work of a good estimate lies.
Where CAPM sits in the industrial-finance toolkit
The CAPM is the upstream source of the cost of equity, and seeing its connections makes the whole financial toolkit coherent. Its output flows directly into the weighted average cost of capital, where the cost of equity is combined with the after-tax cost of debt to give the overall cost of capital. That WACC in turn becomes the discount rate for the net present value and internal rate of return calculators, the hurdle those tools compare projects against, and the capital charge in economic value added.
So a change you make here, in the beta or the market risk premium, ripples all the way through to what a business is worth and which projects clear the bar. Read this way, the CAPM is the starting point of a chain: cost of equity here, cost of capital in the WACC tool, valuation and project appraisal downstream, and value-creation measurement at the end.
Because the tools in this silo share consistent conventions, an estimate made here travels cleanly across all of them, which is the advantage of building a financial picture from one coherent set of assumptions rather than a patchwork.
How analysts use the CAPM in practice
In day-to-day work the CAPM is rarely the last word, but it is almost always the starting point. An equity analyst valuing a company will pull a beta from a data service or estimate one from a regression, choose a risk-free rate that matches the horizon of the cash flows, and adopt a market risk premium from a house view or a published survey, then combine them to get a cost of equity. That figure is fed into a weighted average cost of capital, which discounts the projected cash flows in a valuation model.
Because the answer is sensitive to each input, careful analysts do not report a single number; they run the valuation across a range of betas and premiums to produce a band of values, and they state their assumptions explicitly so that a reader can judge and, if they disagree, adjust them.
The CAPM discipline of separating the risk-free base, the quantity of risk, and the price of risk makes this kind of transparent, testable analysis possible, which is a large part of why the model has endured in practice even as academics have proposed richer alternatives.
Corporate finance teams use the CAPM in much the same spirit when they set hurdle rates for investment. Rather than re-estimating the cost of equity for every small project, a company typically establishes a corporate cost of capital, built on a CAPM cost of equity, and then adjusts it up or down for divisions or projects whose risk differs from the company average.
A capital-intensive, cyclical division might carry a higher beta and therefore a higher hurdle than a stable, contracted business within the same group. This is where the concept of an unlevered or asset beta earns its keep: by stripping out the effect of each comparable company financing and re-levering to the target structure, analysts can build a project-specific cost of equity even when the project itself has no traded shares.
The calculator on this page handles the CAPM arithmetic for any beta you supply, so it serves equally for a quick corporate estimate and for a carefully re-levered project rate.
CAPM, diversification, and portfolio thinking
The CAPM did not arrive in isolation; it grew out of portfolio theory, and understanding that lineage explains why beta, and not total volatility, is the measure of risk it prices.
Portfolio theory showed that combining assets whose returns do not move perfectly together reduces the volatility of the whole portfolio without necessarily reducing its expected return, so a rational investor holds a diversified portfolio and cares only about how each asset contributes to the risk of that portfolio.
An asset own standalone volatility is largely irrelevant if much of it can be diversified away; what matters is the part that moves with everything else, the systematic part, because that is the risk that remains no matter how widely the investor diversifies. Beta captures exactly this contribution, and the CAPM prices it.
This is why a company with wildly volatile earnings can still have a modest cost of equity if that volatility is uncorrelated with the market, and why a steadier company can have a higher cost of equity if its fortunes are tightly tied to the economic cycle.
Keeping the portfolio perspective in mind guards against the common instinct to equate a bumpy share price with a high required return; under the CAPM, only the market-linked bumps are paid for.
Where the CAPM came from
The CAPM was developed in the early 1960s, building on the portfolio theory of the preceding decade, and it earned its authors a Nobel Prize in economics, a mark of how deeply it reshaped the field. Its lasting contribution was to give a precise, testable answer to a question that had previously been treated loosely: how the expected return on an asset should relate to its risk.
By defining risk as the contribution an asset makes to the risk of a diversified portfolio, rather than its standalone variability, and by pricing only that contribution, the model provided a single equation that linked return to risk through beta.
Over the decades that followed, the CAPM was tested exhaustively, and the tests were mixed: the core prediction that higher beta should mean higher return held up only weakly in the data, and researchers found other characteristics, notably company size and the ratio of book value to market value, that predicted returns the CAPM could not explain. Those findings gave rise to the multi-factor models that many practitioners now use alongside or instead of the CAPM for the most demanding work.
Yet the CAPM has not been discarded, and it is worth being clear about why. It remains the most taught, most cited, and most widely applied model of the cost of equity, because its simplicity is a genuine virtue: it requires only three inputs, each with a clear meaning, and it forces the analyst to separate the risk-free rate, the quantity of risk, and the price of risk, which is exactly the discipline good estimation needs.
For the overwhelming majority of practical valuations and hurdle-rate decisions, the CAPM gives a reasonable, defensible cost of equity, and the more elaborate models add complexity that is not always repaid in accuracy.
The pragmatic stance, and the one this calculator supports, is to use the CAPM as the workhorse estimate, understand its assumptions and limits, test the result across a range of inputs, and reach for richer models only when the stakes and the data justify the extra effort.
Frequently asked questions
What is the CAPM?
The capital asset pricing model, or CAPM, is the standard method for estimating the return investors require to hold a risky asset such as a share of stock. It says that this required return, the cost of equity, equals the risk-free rate plus a premium for risk, and that the only risk investors are compensated for is the risk that cannot be diversified away, measured by beta.
In one line, the cost of equity equals the risk-free rate plus beta times the market risk premium. The model is used across finance: to estimate the cost of equity that feeds into a company weighted average cost of capital, to set the discount rate for equity cash flows, and to judge whether an investment offers enough return for its risk.
This calculator applies the CAPM to your inputs and shows the resulting cost of equity, the risk premium, and the security market line.
What is the CAPM formula?
The CAPM formula is: cost of equity equals the risk-free rate plus beta times the market risk premium, where the market risk premium is itself the expected return on the market minus the risk-free rate. Written with symbols, Ke = Rf + β × (Rm − Rf).
The risk-free rate Rf is the return on a safe asset, usually a government bond; beta β measures how much the asset moves with the overall market; and (Rm − Rf) is the extra return investors expect from the market above the risk-free rate.
For example, with a risk-free rate of four percent, a beta of 1.2, and a market risk premium of five percent, the cost of equity is four percent plus 1.2 times five percent, which is ten percent. This calculator lets you enter the market risk premium directly or derive it from an expected market return.
What is beta in the CAPM?
Beta measures an asset systematic risk, meaning how much its returns move in response to movements of the whole market. A beta of one means the asset tends to move in line with the market; a beta above one means it is more volatile than the market, amplifying its swings, so investors demand a higher return; and a beta below one means it is less volatile, a defensive asset that investors accept a lower return on.
A negative beta, which is rare, means the asset tends to move opposite to the market and can act as a hedge. Beta is usually estimated by regressing the asset historical returns against the market returns, or taken from a data provider. Because beta is the only risk the CAPM prices, it is the input that most directly drives the cost of equity, and this calculator marks your asset beta on the security market line.
What is the market risk premium?
The market risk premium is the extra return investors expect from holding the overall stock market instead of a risk-free asset, and it is the reward for bearing market risk. It equals the expected return on the market minus the risk-free rate.
Historically, in developed markets, it has averaged somewhere around four to six percent, though estimates vary with the period and method used, and it is one of the more debated inputs in finance. You can estimate it from long-run historical returns, from forward-looking models, or take a published figure.
In this calculator you can enter the market risk premium directly if you have a view on it, or you can enter an expected market return and let the tool subtract the risk-free rate to derive the premium for you. Because the premium multiplies beta, it has a large influence on the cost of equity, especially for high-beta assets.
What is the risk-free rate?
The risk-free rate is the return on an investment considered to carry no risk of default, used as the baseline from which the risk premium is added. In practice it is proxied by the yield on a government bond of a maturity that matches the investment horizon, commonly the ten-year Treasury note in the United States, the equivalent government bond in Mexico or Brazil, or another sovereign benchmark.
There is no truly risk-free asset, but high-quality government debt is the accepted stand-in. The choice of maturity matters: for valuing a long-lived business, a long-term government bond yield is usually preferred over a short-term rate.
Because the risk-free rate is added to the risk premium and also appears inside the market risk premium, it affects the cost of equity twice, and changes in interest rates flow directly through the CAPM into the cost of equity and hence into valuations.
How does CAPM connect to WACC?
The CAPM is the usual way to produce one of the two main ingredients of the weighted average cost of capital: the cost of equity. WACC blends the cost of equity and the after-tax cost of debt in proportion to how much of each a company uses, and while the cost of debt can often be read from the interest rate on borrowings, the cost of equity has to be estimated, and the CAPM is the standard tool for that.
So in practice the workflow is to estimate the cost of equity here with the CAPM, then carry that figure into the WACC calculator as the cost-of-equity input.
The two tools are designed to be used together: this CAPM calculator produces the number, and the WACC calculator consumes it alongside the cost of debt and the capital-structure weights to give the overall cost of capital used for valuation and investment decisions.
What is the security market line?
The security market line, or SML, is the graphical form of the CAPM. It plots the required return against beta: it starts at the risk-free rate where beta is zero, and rises with a slope equal to the market risk premium, so that at a beta of one the required return equals the expected market return. Every fairly priced asset should lie on this line, its required return determined by its beta.
An asset plotted above the line offers more return than its risk warrants and is attractive, or underpriced; one below the line offers too little for its risk and is unattractive, or overpriced. This calculator draws the security market line for your inputs and marks your asset on it, so you can see at a glance how its required return relates to its systematic risk and to the market as a whole.
What is a country risk premium and when should I add one?
A country risk premium is an extra return added to the cost of equity to compensate investors for the additional political, economic, and currency risk of investing in a particular country, especially an emerging market. The standard CAPM was developed with mature markets in mind, and applying it unmodified to a company in a higher-risk economy would understate the return investors actually require.
For markets such as Mexico or Brazil, analysts often add a country risk premium, frequently derived from the spread between that country sovereign bonds and a benchmark such as US Treasuries, adjusted for equity-market volatility.
This calculator includes an optional country risk premium field so you can apply the emerging-market version of the CAPM: leave it at zero for a standard developed-market estimate, or enter a premium to reflect the added risk of the market you are analysing.
What are the main assumptions and limitations of the CAPM?
The CAPM rests on simplifying assumptions: that investors are rational and diversified, that they can borrow and lend at the risk-free rate, that markets are efficient and frictionless, and that only systematic risk, beta, is priced. Reality departs from these in ways that limit the model.
Beta is estimated from past data and may not predict future sensitivity; the market risk premium is uncertain and debated; and empirical studies find that factors beyond beta, such as company size and value characteristics, also explain returns, which is why multi-factor models exist.
Despite these limitations, the CAPM remains the most widely used and taught method for the cost of equity because it is simple, transparent, and captures the central insight that return should compensate for non-diversifiable risk. It is best treated as a well-founded estimate, tested across a range of inputs, rather than a precise truth.
Does this calculator store the numbers I enter?
No. The calculator runs entirely in your browser. The risk-free rate, beta, market risk premium, and any other values you enter are never sent to our servers, stored, or shared. You can use it freely for confidential figures. See our Privacy Policy for details.
Is the CAPM calculator free to use?
Yes. This calculator, like every tool on OpsCalculators, is free and needs no account or sign up. There is no paywall and no limit on how many calculations you can run, and you can adjust the inputs as often as you like to test different scenarios.
How do I estimate beta for a company?
Beta is most commonly estimated by statistical regression of a stock historical returns against the returns of a broad market index over a period such as two to five years, where the slope of the fitted line is the beta. For public companies, beta is also published by financial data providers, so you can often simply look it up.
For a private company or a project, analysts take the average beta of comparable public companies in the same industry, remove the effect of each comparable capital structure to get the unlevered or asset beta, and then re-lever it to the target company own debt-to-equity mix. Whatever the source, beta is an estimate and worth sensitivity-testing.
Enter your chosen beta in this calculator to see how it drives the cost of equity, and try a range to understand how sensitive the result is.
Related industrial finance calculators
More tools in this silo. Return to the Industrial Finance hub for the full set.
Sources, disclaimer and editorial transparency
Method follows the standard treatment of the capital asset pricing model in corporate finance, including the texts by Brealey, Myers and Allen and by Damodaran, and the definitions used by the CFA Institute and the Corporate Finance Institute. See our Editorial Policy for how we research and review each tool.
This calculator is for education and planning and does not constitute financial, tax, or investment advice. Confirm any figure that informs a real decision with a qualified professional. OpsCalculators is operated by MAFHH INTERNATIONAL LTD; see our Privacy Policy.