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Industrial Finance
WACC Calculator (Weighted Average Cost of Capital)
In short: the weighted average cost of capital (WACC) is the blended return a company must earn to satisfy its lenders and shareholders, and the discount rate most valuations use. This calculator computes it from the market value and cost of debt, equity, and optional preferred equity, applies the interest tax shield, and shows the capital-structure weights, the after-tax cost of debt, and each source’s contribution.
The WACC formula
WACC = (E ÷ V) × Re + (D ÷ V) × Rd × (1 − t), where V = E + D (+ preferred), Re is the cost of equity, Rd the cost of debt, and t the tax rate.
The weighted average cost of capital, or WACC, is the single most important rate in corporate finance: the blended return a company must earn to satisfy everyone who funds it, and the discount rate that nearly every valuation and investment decision relies on. A business raises money from lenders, who charge interest, and from shareholders, who expect a return for the risk they take, and the WACC combines the cost of both in proportion to how much of each the company uses.
This calculator computes the WACC from your capital structure, the market values of equity and debt, their costs, the tax rate, and, optionally, preferred equity, and it shows the weights, the after-tax cost of debt, and each source’s contribution so you can see exactly how the figure is built. In Spanish this is the CPPC and in Portuguese the CMPC; the concept and the arithmetic are the same everywhere.
Whether you are valuing a business, setting a hurdle rate for capital projects, or judging whether operations are creating value, the WACC is the number the analysis begins with, and getting it right, on market values, after tax, with a defensible cost of equity, is the difference between an appraisal that stands up and one that quietly misleads.
What WACC means
Every company is funded by a mix of capital, and each source has a price. Lenders must be paid interest, and shareholders, though promised nothing, expect a return that compensates them for the risk of ownership.
The weighted average cost of capital is simply the average of these costs, weighted by how much of each kind of capital the company uses, and it answers a fundamental question: what return must the business earn on its assets and investments just to keep its investors whole? A company that earns exactly its WACC creates no value and destroys none; one that earns more creates value, and one that earns less destroys it, however healthy its accounting profit may look.
This is why the WACC is the benchmark at the centre of corporate finance, the line between value creation and value destruction, and why getting it right matters so much.
The WACC formula
The formula weights each source of capital by its share of the total and multiplies by that source’s cost. In the standard two-source form, WACC equals the proportion of equity times the cost of equity, plus the proportion of debt times the after-tax cost of debt. The proportions, or weights, are the market value of each source divided by the total value of all capital, so if a company is funded sixty percent by equity and forty percent by debt, those are the weights.
The cost of equity is the return shareholders require; the cost of debt is the interest rate, reduced by the tax shield described below. When a company also issues preferred equity, a third term is added for its weight and cost, and this calculator handles that case.
Worked through for sixty percent equity at a twelve percent cost and forty percent debt at a six percent pre-tax cost with a thirty percent tax rate, the WACC comes to about 8.88 percent, and the calculator lays out each weight and contribution behind that result.
The interest tax shield
A crucial feature of the WACC is that the cost of debt is used on an after-tax basis. Interest paid on borrowing is a tax-deductible expense, so taking on debt reduces a company taxable income and therefore its tax bill, a saving known as the interest tax shield. The true cost of debt to the company is therefore lower than the interest rate the lender charges, by exactly the tax that the interest deduction saves.
To capture this, the pre-tax cost of debt is multiplied by one minus the tax rate: debt at six percent for a company paying thirty percent tax has an after-tax cost of 4.2 percent. The higher the tax rate, the larger the shield and the cheaper debt becomes on an after-tax basis.
This tax advantage is a major reason debt is often a cheaper source of capital than equity, and it is why the financing mix a company chooses feeds directly into its cost of capital.
Cost of equity versus cost of debt
The two costs that go into the WACC are estimated very differently. The cost of debt is relatively easy to observe: it is the interest rate the company pays, which can be read from its loans and bonds, and then adjusted for the tax shield. The cost of equity is harder, because shareholders are not promised a fixed return; it is the return they require for the risk of holding the shares, and it must be estimated, most often with the capital asset pricing model.
That model builds the cost of equity from the risk-free rate, the company beta, which measures how much its shares move with the market, and the market risk premium. The cost of equity is almost always higher than the cost of debt, for two reasons: equity holders bear more risk, since they are paid only after lenders in a wind-up, and equity carries no tax shield. Because equity is the more expensive source, a company reliance on it strongly influences the WACC.
Market values, not book values
The weights in the WACC should be based on market values, not the book values recorded on the balance sheet, because the WACC is meant to reflect the cost of raising capital today, which depends on what investors would pay now. The market value of equity is the current share price times the number of shares, or a valuation estimate for a private company, and it can differ enormously from the book value of equity, which is merely historical.
The market value of debt is what the debt would sell for, often close to book value for ordinary bank loans but different for traded bonds when interest rates have shifted since issue. Using book values, especially for equity, distorts the weights and produces a misleading WACC.
In practice the book value of debt is frequently accepted as an approximation, but the equity weight should rest on market value wherever it can be obtained, which is why this calculator asks for market values.
WACC and the valuation of a business
The most important use of the WACC is as the discount rate in a discounted cash-flow valuation. To value a business or a project, its expected future cash flows are discounted back to the present, and the WACC is the rate used to do the discounting, because it represents the return all the providers of capital collectively require.
A higher WACC discounts future cash flows more heavily and produces a lower valuation, while a lower WACC raises it, so the WACC is one of the most influential inputs in any valuation, and a small change in it can move the answer substantially.
This is why analysts take such care in estimating it, and why the WACC sits upstream of the net present value calculation: the discount rate that the net present value tool asks for is, for most business valuations, exactly this WACC. The two tools in this network are designed to be used together.
WACC as a hurdle rate
Beyond valuation, the WACC serves as the hurdle rate for deciding which investments to make. Because the WACC is the cost of the capital that would fund a project, a project only adds value if it earns more than the WACC; one that returns less than the cost of the capital it consumes destroys value even if it shows an accounting profit.
In practice a company compares a project internal rate of return against the WACC and accepts it only if the return clears that bar, or equivalently checks that the project net present value, computed at the WACC, is positive. This is the link between the WACC and the capital-budgeting tools: the WACC sets the threshold, and the internal-rate-of-return and net-present-value calculators test individual projects against it.
A common refinement is to raise or lower the hurdle for projects that are riskier or safer than the company as a whole.
Capital structure and the optimal mix
Because debt and equity cost different amounts, the mix of the two, the capital structure, affects the WACC. Debt is typically the cheaper source, both because lenders bear less risk than shareholders and because of the tax shield, so replacing some equity with debt tends to pull the WACC down at first.
But debt is not free of consequences: as a company borrows more, its financial risk rises, and both shareholders and, eventually, lenders demand higher returns to compensate, which pushes the costs of equity and debt up. The net effect is a WACC that generally falls as moderate debt is introduced, bottoms out at an optimal capital structure that minimises the cost of capital, and then climbs as excessive leverage makes the whole enterprise riskier.
Judging this trade-off is one of the central tasks of corporate finance, and experimenting with the debt and equity inputs in this calculator makes the relationship concrete.
When WACC is and is not the right rate
The company-wide WACC is the correct discount rate only for projects that share the average risk and financing of the business. It reflects the blended risk of everything the company does, so applying it to a project that is markedly riskier or safer will misjudge that project, treating a risky venture too generously or penalising a safe one.
In such cases analysts use a project-specific or division-specific cost of capital, often estimated from the betas of comparable pure-play companies, rather than the corporate WACC. Similarly, a project financed very differently from the company norm calls for weights that match its own financing.
For the ordinary case, a typical project inside an established business with a stable capital structure, the corporate WACC is the appropriate rate and is used almost universally. Knowing when the standard WACC applies, and when a tailored rate is needed, is part of using it well.
WACC versus the cost of equity: which rate to use
A common point of confusion is whether to discount at the WACC or at the cost of equity, and the answer depends on which cash flows you are valuing. The WACC is the rate for the cash flows available to all providers of capital, the unlevered free cash flow of the whole business before any payments to lenders, because the WACC blends the returns required by lenders and shareholders alike.
The cost of equity, by contrast, is the rate for the cash flows available only to shareholders, the levered free cash flow that remains after interest and debt repayments, because only equity holders have a claim on it. Matching the two correctly is essential: discounting whole-firm cash flows at the cost of equity, or equity cash flows at the WACC, produces a wrong valuation.
Most business and project valuations use the whole-firm approach and therefore the WACC, which is why it is the default discount rate; equity-only valuation with the cost of equity is more common in banking and for highly leveraged situations where the financing itself is the very point of the analysis and the returns to lenders are treated separately.
Keeping this distinction clear also explains why the WACC uses the after-tax cost of debt while the cost of equity carries no such adjustment: the tax shield belongs to the whole firm and is captured in the WACC, whereas equity cash flows are already measured after the interest that generates the shield.
Getting the pairing of cash flow and discount rate right is one of the marks of a sound valuation, and the WACC this calculator produces is built for the whole-firm case that the great majority of appraisals use. In short, if the cash flows belong to everyone who funded the business, discount at the WACC; if they belong to shareholders alone, discount at the cost of equity.
That single rule resolves most of the confusion around which rate to apply, and it keeps the valuation internally consistent, which matters far more than any refinement to the individual inputs.
Where WACC sits in the industrial-finance toolkit
The WACC is the hub around which much of industrial finance turns, and seeing those connections makes the whole toolkit coherent. Its own most important input, the cost of equity, comes from the CAPM calculator, so in practice you compute the cost of equity first and bring it here. Downstream, the WACC feeds the discounted cash-flow valuation that the net present value and internal rate of return calculators perform, supplying the discount rate and the hurdle those tools compare against.
It is the capital charge in the economic value added calculator, the line that turns an accounting profit into a measure of true value creation. And it provides context for the return calculators, since a return on invested capital is only good news if it exceeds the WACC.
Read this way, the WACC is not an isolated formula but the connective tissue of corporate finance: estimate it well and a whole family of decisions, what a business is worth, which projects to fund, whether performance is creating value, rests on firm ground.
This is also why it is the flagship of the industrial-finance silo and the first tool to launch here. The other calculators in the silo either feed it, as the CAPM does, or consume it, as valuation, project appraisal, and value-added analysis do. Because they share consistent conventions, a cost of capital estimated here can travel across all of them, letting you build a complete financial picture, from the cost of money to the value it creates, from one coherent set of assumptions rather than a patchwork of disconnected calculations.
Assumptions and limitations of WACC
For all its central importance, the WACC rests on assumptions that mark the limits of its use. It assumes a stable capital structure, the same mix of debt and equity over the period being valued, whereas a company that is deliberately changing its leverage will have a WACC that drifts, and valuing it properly may call for more advanced methods that adjust the rate each year.
It assumes the cost of equity can be estimated reliably, yet that estimate, usually from the capital asset pricing model, depends on a beta and a market risk premium that are themselves uncertain, so the WACC is only ever as good as those inputs. It assumes the project or business being discounted has the same risk as the company average, which fails for unusually risky or safe ventures.
And it treats the tax shield as fully usable, which requires the company to be profitable enough to use its interest deductions. None of these undermines the WACC as the standard tool; they simply mark where care is needed.
The practical response to these limitations is not to abandon the WACC but to use it thoughtfully: test a range of costs of equity rather than trusting one, use a project-specific rate when risk differs markedly from the company average, and revisit the figure when the capital structure or the interest-rate environment changes. Treated as a well-founded estimate rather than an exact constant, the WACC remains the indispensable rate at the centre of valuation and investment decisions.
Five worked examples from real capital structures
Example 1: a balanced mid-size manufacturer
Equity is 60% at a 12% cost, debt 40% at 6% pre-tax, tax 30%. After-tax cost of debt is 6% × (1 − 0.30) = 4.2%. WACC = 0.60 × 12% + 0.40 × 4.2% = 7.2% + 1.68% = 8.88%.
Example 2: a debt-heavy utility
A regulated utility funds 30% equity at 10% and 70% debt at 5%, tax 25%. After-tax debt is 5% × 0.75 = 3.75%. WACC = 0.30 × 10% + 0.70 × 3.75% = 3.0% + 2.625% = 5.63%. Cheap, tax-shielded debt pulls the WACC well below the equity cost.
Example 3: an all-equity startup
A young company carries no debt and funds entirely with equity at an 18% required return. With no debt weight and no tax shield, the WACC is simply the cost of equity, 18%. The high figure reflects the risk investors price into a young business.
Example 4: a firm with preferred stock
Capital is 50% common equity at 12%, 10% preferred at 8%, and 40% debt at 7% pre-tax, tax 30%. After-tax debt is 7% × 0.70 = 4.9%. WACC = 0.50 × 12% + 0.10 × 8% + 0.40 × 4.9% = 6.0% + 0.8% + 1.96% = 8.76%.
Example 5: the same firm in a higher-tax country
Take Example 1 but raise the tax rate to 40%. After-tax debt falls to 6% × 0.60 = 3.6%, so WACC = 0.60 × 12% + 0.40 × 3.6% = 7.2% + 1.44% = 8.64%. A higher tax rate deepens the interest tax shield and lowers the WACC.
Three expert tips for a defensible WACC
Weight with market values, not book values
Use the market value of equity (share price × shares, or a valuation) and of debt, not their balance-sheet figures. Book weights, especially for equity, distort the mix and produce a misleading WACC.
Match the rate to the project’s risk
The company-wide WACC fits a project only if it shares the firm’s average risk and financing. For a markedly riskier or safer project, use a division- or project-specific cost of capital instead.
Refresh it when markets move, and test a range
The WACC drifts with interest rates and the cost of equity, both of which are estimates. Recompute it when rates or the capital structure change, and test a range on the cost of equity rather than trusting one figure.
WACC, EVA and value creation
The WACC is the yardstick that separates value creation from value destruction, and this is made explicit in economic value added. A business creates value only when it earns more on its capital than that capital costs, that is, when its return on invested capital exceeds its WACC.
Economic value added measures this directly: it is the operating profit after tax minus a charge equal to the capital employed times the WACC, so a positive EVA means the business has beaten its cost of capital and genuinely added value, while a negative EVA means it has fallen short even if it reported an accounting profit.
This is why the WACC is not just a discounting convenience but a fundamental benchmark of performance, and why it sits at the heart of how modern companies judge whether their operations and investments are worthwhile. The economic value added calculator in this silo uses exactly the WACC this tool computes as its capital charge, so the two are designed to work together.
WACC across countries and interest-rate environments
The WACC is not a fixed number even for the same business, because it moves with the environment. When central-bank interest rates rise, the risk-free rate that anchors the cost of equity climbs and the interest rate on new debt rises too, so the WACC increases and valuations fall; when rates drop, the reverse happens.
Country matters as well: a company operating in an emerging market such as Mexico or Brazil typically faces a higher WACC than an otherwise identical firm in a low-rate developed market, because both lenders and equity investors demand a country-risk premium for the added political, currency, and economic uncertainty. Analysts often add an explicit country-risk premium to the cost of equity for these markets.
The practical lesson is that a WACC computed today reflects today conditions, and it should be revisited when interest rates or the risk environment shift materially, which the calculator makes easy by recomputing instantly as you change the inputs.
How each input moves the WACC
Because the WACC is a weighted average of a handful of inputs, it is worth knowing how each one moves it. A higher cost of equity raises the WACC in proportion to the equity weight, and since equity is usually the largest and most expensive component, the cost of equity is often the input the WACC is most sensitive to. A higher cost of debt raises the WACC through the debt weight, but its effect is muted by the tax shield.
A higher tax rate lowers the WACC, because it deepens the tax shield and cheapens debt on an after-tax basis. Shifting the mix toward debt lowers the WACC as long as debt stays cheaper than equity, which is the usual case, though only up to the point where rising risk begins to push the component costs up.
Testing these sensitivities, by changing one input at a time in the calculator and watching the WACC respond, quickly reveals which assumptions matter most and where to focus estimation effort, since the cost of equity in particular is only ever an estimate.
Common mistakes to avoid
Several errors recur with WACC. The first is using book values instead of market values for the weights, especially for equity, which distorts the result; use market values wherever possible. The second is forgetting the tax shield and putting the pre-tax cost of debt into the formula, which overstates the WACC; always use the after-tax cost of debt.
The third is mismatching the numerator and the rate, for example discounting cash flows that are available to all investors at a rate that reflects only equity, or vice versa; the unlevered free cash flow to the whole firm is what the WACC discounts. The fourth is applying the company WACC to a project of very different risk, which mis-values it.
And the fifth is treating the WACC as a fixed constant, when it changes as interest rates, the capital structure, and the company risk change; recompute it when conditions move. The calculator handles the arithmetic correctly, but these judgments are yours to make.
Frequently asked questions
What is WACC?
WACC, the weighted average cost of capital, is the average rate of return a company must pay to all the investors who fund it, both lenders and shareholders, weighted by how much of each kind of capital it uses. It represents the blended cost of the money a business runs on, and it is the minimum return the company must earn on its investments to avoid destroying value.
Because it captures the cost of both debt and equity in one figure, WACC is used everywhere in corporate finance: it is the discount rate in a discounted cash-flow valuation, the hurdle rate a project must clear, and the benchmark against which returns on capital are judged. In Spanish it is the CPPC, the costo promedio ponderado de capital, and in Portuguese the CMPC, the custo médio ponderado de capital; the concept and formula are identical.
This calculator computes it from your capital structure, costs, and tax rate.
What is the WACC formula?
The WACC formula weights the cost of each source of capital by its share of the total. In its common form it is the proportion of equity times the cost of equity, plus the proportion of debt times the after-tax cost of debt: WACC equals (E divided by V) times the cost of equity, plus (D divided by V) times the cost of debt times one minus the tax rate, where V is the total value, the sum of equity E and debt D.
The cost of debt is multiplied by one minus the tax rate because interest is tax-deductible, which lowers its effective cost. When a company also has preferred equity, a third term is added, the proportion of preferred times its cost, and this calculator supports that three-source version.
For a firm with sixty percent equity at a twelve percent cost and forty percent debt at a six percent pre-tax cost with a thirty percent tax rate, the WACC works out to about 8.88 percent.
Why is the cost of debt multiplied by (1 − tax rate)?
Interest paid on debt is a tax-deductible expense, so borrowing reduces a company taxable income and therefore its tax bill. This tax saving, called the interest tax shield, lowers the true, effective cost of debt below the interest rate the lender charges.
Multiplying the pre-tax cost of debt by one minus the tax rate converts it into this after-tax cost, which is what belongs in the WACC because it reflects the real burden of the debt on the company after the tax benefit. For example, debt at a six percent interest rate for a company paying thirty percent tax has an after-tax cost of six percent times seventy percent, or 4.2 percent.
This tax advantage is one reason debt is often a cheaper source of capital than equity, and why a company financing mix affects its overall cost of capital.
What is the difference between the cost of equity and the cost of debt?
The cost of debt is straightforward: it is the interest rate a company pays its lenders, reduced by the tax shield, and it is relatively easy to observe from the interest on the company borrowings. The cost of equity is subtler, because shareholders are not promised a fixed return; instead it is the return they require for bearing the risk of owning the shares, which must be estimated.
The most common method is the capital asset pricing model, which builds the cost of equity from the risk-free rate, the company sensitivity to market movements known as beta, and the extra return the market demands over the risk-free rate. The cost of equity is almost always higher than the cost of debt, because equity holders take more risk, being paid only after lenders, and because they receive no tax shield.
WACC blends the two according to how much of each the company uses.
Should I use market values or book values for the weights?
Market values are the correct basis for the WACC weights, because WACC is meant to reflect the current cost of raising capital, and that depends on what investors would pay today, not on historical accounting figures.
The market value of equity is the share price times the number of shares, or an estimate of what the equity is worth; the market value of debt is what the debt would trade for, often close to its book value for ordinary loans but different for bonds when interest rates have moved.
Book values, taken from the balance sheet, can differ substantially from market values, especially for equity, and using them distorts the weights and therefore the WACC. In practice book value of debt is often used as a reasonable approximation, but the equity weight should be based on market value wherever possible. Enter market values in this calculator for the most accurate result.
What is WACC used for?
WACC has three main uses. First and most important, it is the discount rate in a discounted cash-flow valuation: future cash flows of a business or project are discounted at the WACC to find their present value, so the WACC directly determines what the business is worth.
Second, it is the hurdle rate for capital budgeting: a project should be accepted only if its return, its internal rate of return, exceeds the WACC, because otherwise it earns less than the capital costs. Third, it is a performance benchmark: comparing a company return on invested capital against its WACC reveals whether the business is creating or destroying value, which is the basis of economic value added.
Because of these uses, the WACC connects directly to the net present value, internal rate of return, and economic value added calculators, all of which rely on it as the cost-of-capital input.
How does capital structure affect WACC?
Capital structure, the mix of debt and equity a company uses, affects the WACC because debt and equity have different costs. Debt is usually cheaper, both because lenders take less risk than shareholders and because of the tax shield, so adding debt to the mix tends to lower the WACC at first.
However, more debt also raises the financial risk of the company, which pushes up both the cost of equity, as shareholders demand more for the greater risk, and eventually the cost of debt itself as lenders grow wary. The result is that WACC typically falls as modest debt is added, reaches a minimum at some optimal capital structure, and then rises as excessive debt makes the whole company riskier.
Understanding this trade-off is central to financing decisions, and changing the debt and equity mix in this calculator shows how the WACC responds.
Can WACC be used as the discount rate for any project?
WACC is the right discount rate for a project only when the project has roughly the same risk as the company as a whole and is financed in the same proportions of debt and equity. That is because WACC reflects the average risk and financing of the whole business.
For a project that is significantly riskier or safer than the company average, using the company-wide WACC would misjudge it, discounting a risky project too lightly or a safe one too heavily, so a project-specific or division-specific cost of capital should be used instead. Likewise, if a project is financed very differently from the firm norm, the weights should reflect that.
For the common case of a typical project within an established business, though, the company WACC is the appropriate and widely used discount rate, which is what this calculator computes.
Does this calculator store the numbers I enter?
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Is the WACC 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 export your results to CSV or save a PDF at no cost.
How do I estimate the cost of equity for the WACC?
The cost of equity, the return shareholders require, is usually estimated with the capital asset pricing model, or CAPM. It adds to the risk-free rate, typically the yield on a government bond, a risk premium equal to the company beta times the market risk premium.
Beta measures how much the company shares move relative to the overall market, so a beta above one means the stock is more volatile than the market and its owners demand a higher return. The market risk premium is the extra return investors expect from the stock market over the risk-free rate, historically a few percentage points.
Because estimating the cost of equity is a calculation in its own right, this silo has a dedicated CAPM and cost-of-equity calculator; compute it there and enter the result as the cost of equity here in the WACC calculator.
What is a typical WACC value?
There is no single typical WACC, because it depends heavily on the industry, the country, interest rates, and the company capital structure and risk. That said, for large, stable companies in developed markets the WACC often falls somewhere in the high single digits to low teens as a percentage, reflecting moderate costs of debt and equity.
Riskier businesses, smaller companies, and firms in higher-interest-rate or higher-risk economies have higher WACCs, sometimes well into the teens or beyond, because both lenders and shareholders demand more. The right comparison is never against a supposed universal figure but against the returns the business actually earns and the WACC of comparable companies.
What matters is that the business consistently earns more than its own WACC, whatever that figure is, because that is the definition of creating value.
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 weighted average cost of capital in corporate finance, including the texts by Brealey, Myers and Allen and by Damodaran, and the definition 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.