Weighted Average Cost of Capital Calculator
Solve WACC = (E/V)·Re + (D/V)·Rd·(1 − Tax) for any of its six quantities — the weighted average cost of capital, the equity value, the debt value, the cost of equity, the cost of debt, or the corporate tax rate. Includes a live capital structure and cost-of-capital diagram, a WACC-vs-leverage chart, and a full step-by-step solution.
It is a weighted average of two sources of capital
WACC blends the cost of equity (typically the higher of the two) and the after-tax cost of debt into a single rate, weighting each by its share of total capital. Because debt interest is tax-deductible, its effective cost is lower than its stated rate, which is why companies can lower their WACC by using more debt — up to a point. But as leverage rises, both equity holders and lenders demand higher returns to compensate for the added risk, so WACC does not fall indefinitely. The optimum capital structure is where WACC is minimised.
The tax shield is what makes debt cheap
Interest payments are deducted from pre-tax income, so a company with a 21 % tax rate saves 21 cents of tax for every dollar of interest it pays. That effectively reduces the cost of debt from Rd to Rd·(1−0.21) = 0.79·Rd. A 5 % loan therefore costs only 3.95 % on an after-tax basis. This tax shield is why WACC is usually stated as a blended after-tax rate — it reflects the actual cash cost to the company after taking tax savings into account. If the company has no taxable income, or the tax rate is zero, the shield disappears.
It is the discount rate for enterprise value
WACC is the correct discount rate for free cash flow to the firm (FCFF) in a discounted cash flow valuation. The resulting present value is enterprise value (EV) — the value of the whole business to all capital providers. To get to equity value, subtract net debt from EV. Using WACC as the discount rate ensures that the value produced reflects the blended required return of both debt and equity holders. Some companies also use WACC as a hurdle rate for capital budgeting decisions: a project adds value only if its return exceeds WACC.
It must be updated as market conditions change
WACC is not a fixed number. It moves with interest rates, credit spreads, equity risk premiums, the company's beta, its leverage ratio, and the tax regime. During rate-hike cycles, both Rd and Rf rise, pushing WACC higher and reducing the present value of future cash flows. During market stress, the equity risk premium widens, again raising WACC. For this reason, WACC must be recomputed at each valuation date; using a stale WACC is one of the most common errors in DCF modelling.
How to Use This Calculator
The WACC formula links six quantities: the weighted average cost of capital, equity value E, debt value D, cost of equity Re, cost of debt Rd, and tax rate. Give the tool five and it will find the sixth.
1. Load a company preset
Click any preset — large-cap tech, utility, retailer, small business, real estate, startup, etc. — to load representative capital structure and cost-of-capital values in one click.
2. Enter the capital structure
Equity value E is the market cap. Debt value D is the market value of interest-bearing debt. Both must be in the same currency. V = E + D is computed automatically.
3. Enter cost of equity and cost of debt
Re is the required equity return (often derived from CAPM). Rd is the pre-tax borrowing rate (yield-to-maturity on bonds, or rate on comparable new debt). The tax rate drives the debt tax shield.
4. Choose what to solve for
Pick WACC to compute the blended rate; E, D, Re, Rd, or Tax to reverse-engineer any single input from the others.
5. Read the result and the diagram
The result card shows the primary value plus a colour-coded verdict based on the WACC level and the capital structure. The diagram below draws the capital structure bar and the cost-of-capital number line, showing how WACC sits between the after-tax cost of debt and the cost of equity.
6. Switch to Advanced for depth
Advanced mode adds a WACC-vs-Re chart, a +1 % sensitivity check on each input, and a companion metrics panel with E/V, D/V, the debt tax shield, the after-tax cost of debt, and the spread between WACC and Re.
What This Tool Offers
Built around the classic WACC relation WACC = (E/V)·Re + (D/V)·Rd·(1 − Tax), the standard corporate-finance measure of a firm's blended cost of capital.
Six-way solving
Solve for WACC, E, D, Re, Rd, or Tax. The calculator rearranges the formula automatically and enforces the physical constraints (Re ≥ Rd·(1−Tax), WACC between the two bounds, etc.).
Capital structure + number line
A live visual: a stacked bar showing E/V vs D/V at the top, and a cost-of-capital number line at the bottom with markers for Rd·(1−Tax), WACC, and Re.
WACC vs leverage chart
The classic capital-structure trade-off chart: shows how WACC, equity contribution, and debt contribution vary as the D/V ratio changes, all in one view.
Tax shield metrics
Reports the debt tax shield (1 − Tax), the after-tax cost of debt, and the spread between WACC and both components. Useful for capital-budgeting and valuation work.
Company preset library
Nine presets spanning the capital-structure spectrum: large-cap tech, utility, manufacturer, retailer, telecom, small business, real estate, startup, and a custom slot.
Reference tables
A WACC lookup grid across leverage ratios and Re/Rd spreads, typical cost-of-equity and cost-of-debt values by sector, and a comprehensive FAQ.
Reference Tables & Conversions
A WACC lookup grid, typical values by sector, and the variable reference.
WACC Lookup Grid — Tax = 21 %
WACC at various debt-to-capital ratios, cost of equity, and cost of debt. Values in % per year.
Typical Costs by Sector
Representative cost of equity, cost of debt, and capital structure for major industry groups. Actual values vary widely with market conditions and company specifics.
| Sector | Cost of equity Re | Cost of debt Rd | Typical D/V | Typical WACC |
|---|
Variable Reference
| Symbol | Meaning | Formula | Notes |
|---|---|---|---|
| WACC | Weighted average cost of capital | (E/V)·Re + (D/V)·Rd·(1−T) | The blended after-tax discount rate |
| E | Equity value (market cap) | — | Shares × price for public companies |
| D | Debt value (interest-bearing) | — | Bonds, loans, notes, finance leases |
| V | Total capital | E + D | The denominator of the weights |
| Re | Cost of equity | Rf + β·(Rm − Rf) | Often from CAPM |
| Rd | Pre-tax cost of debt | YTM on bonds, or new borrowing rate | Investment-grade: 3–6 %; high-yield: 7–12 % |
| Tax | Marginal corporate tax rate | — | Drives the interest tax shield |
| (1−Tax) | Debt tax shield factor | — | Multiplies Rd to get after-tax cost of debt |
| E/V | Equity weight | E/(E+D) | Share of capital from equity |
| D/V | Debt weight (leverage) | D/(E+D) | Share of capital from debt |
What Does WACC = (E/V)·Re + (D/V)·Rd·(1 − Tax) Measure?
The Weighted Average Cost of Capital is the blended after-tax rate of return a company must earn on its existing asset base to satisfy its creditors, owners, and other capital providers. It is a weighted average of the cost of equity (the return shareholders require) and the after-tax cost of debt (the return lenders require, adjusted for the fact that interest is tax-deductible), with the weights being each source's share of total capital. It is the single most important number in corporate finance — the discount rate for enterprise DCF valuations, the hurdle rate for capital budgeting, and the benchmark for economic profit.
The WACC Formula
The defining relationship is:
where V = E + D. Each term has a clear interpretation:
D/V = debt weight (leverage)
Rd·(1 − Tax) = after-tax cost of debt
Rearranged to solve for the other five quantities:
Rd = [ WACC − (E/V)·Re ] / [ (D/V)·(1−Tax) ]
Tax = 1 − [ WACC − (E/V)·Re ] / [ (D/V)·Rd ]
E = x · D / (1 − x) where x = [ WACC − Rd(1−Tax) ] / [ Re − Rd(1−Tax) ]
D = y · E / (1 − y) where y = [ Re − WACC ] / [ Re − Rd(1−Tax) ]
WACC Variables
| Symbol | Meaning | Notes |
|---|---|---|
| WACC | Weighted average cost of capital | Blended after-tax discount rate |
| E | Equity value | Market value of equity, not book value |
| D | Debt value | Interest-bearing debt only |
| V | Total capital | E + D |
| Re | Cost of equity | Higher than Rd in normal capital structures |
| Rd | Pre-tax cost of debt | Effective cost is Rd·(1−Tax) |
| Tax | Corporate tax rate | Drives the interest tax shield |
How Each Input Affects WACC
WACC is a weighted average, so its value always lies between the after-tax cost of debt (lower bound) and the cost of equity (upper bound). When E/V = 1 (all equity), WACC = Re. When D/V = 1 (all debt), WACC = Rd·(1−Tax). Any mix produces a value between those two extremes.
Raising the cost of equity lifts WACC, but the effect is scaled by E/V: at 90 % equity weight, a 1 % rise in Re lifts WACC by 0.9 %. Raising the cost of debt lifts WACC, scaled by D/V·(1−Tax): at 30 % debt weight and a 21 % tax rate, a 1 % rise in Rd lifts WACC by only 0.24 %. Tax rate has the opposite effect: higher tax rates make debt cheaper and therefore lower WACC (for a given capital structure), because the tax shield grows.
Leverage ratio has a subtler effect. Naively, shifting capital from equity to debt lowers WACC because debt is cheaper. But in practice, higher leverage raises both Re (equity holders demand more return for financial risk) and Rd (lenders demand more for default risk). The net effect is a U-shaped WACC curve: WACC falls initially as cheap debt replaces expensive equity, reaches a minimum at the optimal capital structure, then rises as the financial-distress premium dominates. This trade-off theory of capital structure is one of the central insights of corporate finance.
WACC Calculation Examples
V = $110B · E/V = 90.9 % · D/V = 9.1 %
Equity term = 0.909 × 10 % = 9.09 %
Debt term = 0.091 × 5 % × 0.79 = 0.36 %
WACC = 9.45 %
V = $70B · E/V = 42.9 % · D/V = 57.1 %
Equity term = 0.429 × 9 % = 3.86 %
Debt term = 0.571 × 5 % × 0.79 = 2.26 %
WACC = 6.12 %
V = $55M · E/V = 90.9 % · D/V = 9.1 %
Equity term = 0.909 × 25 % = 22.73 %
Debt term = 0.091 × 10 % × 1.00 = 0.91 %
WACC = 23.64 %
Re = [ 8 − (0.5)·5·0.79 ] / 0.5 = [ 8 − 1.975 ] / 0.5 = 12.05 %
Frequently Asked Questions
Because interest payments are tax-deductible. If a company earns $100 of pre-tax income and pays $20 of interest, it only pays tax on $80. At a 21 % rate, that means a tax bill of $16.80 instead of $21 — a saving of $4.20, which is exactly 21 % of the $20 interest. So the effective after-tax cost of the $20 of interest is $20 − $4.20 = $15.80, or 79 % of the pre-tax cost. The same logic applies to any amount of interest: the after-tax cost is Rd·(1 − Tax). This tax shield is why debt is cheaper than equity in most capital structures, and why WACC falls as leverage increases (up to the point where distress costs dominate). If the company has no taxable income (e.g., an early-stage startup with accumulated losses), the tax rate is effectively zero and the shield has no value.
Market value, whenever possible. WACC measures the cost of raising new capital, and market prices reflect what investors actually require today. Book value of equity (shareholders' equity on the balance sheet) reflects historical accounting and can be wildly different from market cap — often a fraction of it for asset-light companies. Book value of debt is usually closer to market value, especially for short-term or recently-issued debt, so it is often used as a practical proxy. If market values are unavailable (common for private companies), use book values and adjust downward the resulting E/V ratio to approximate a market-based weighting, or estimate the market value of equity from comparable public companies.
The required return on equity (Re) is what equity investors demand for holding the company's stock. WACC is the blended required return of ALL capital providers — equity holders AND debt holders — weighted by their share of total capital. Because debt is cheaper (both inherently and through the tax shield), WACC is always below Re whenever the company has any debt. The two are equal only for an all-equity company. This difference matters: use Re to discount cash flows to equity (FCFE), and use WACC to discount cash flows to the firm (FCFF). Mixing them up — using Re to discount FCFF, or WACC to discount FCFE — is one of the most common DCF errors.
The most common method is the Capital Asset Pricing Model (CAPM): Re = Rf + β·(Rm − Rf). Rf is the risk-free rate — usually the yield on a 10-year government bond. β measures the stock's sensitivity to market movements; 1.0 is average, 0.5 is defensive, 1.5–2.0 is aggressive, and some companies (e.g., biotech) can have betas above 2. Rm − Rf is the equity risk premium, typically estimated from long-run historical returns at 4–6 % for developed markets. For private companies, an adjusted CAPM adds a small-size and illiquidity premium. Alternative methods include the dividend discount model (Re = D₁/P₀ + g) and the bond yield plus risk premium approach.
Not automatically. A lower WACC means capital is cheaper, which raises the present value of any given set of future cash flows. But if the WACC is low because the company has loaded up on debt, the reduction in WACC may be more than offset by higher financial distress risk. Modigliani–Miller's trade-off theory says the optimal capital structure minimises WACC while keeping the probability of financial distress acceptably low. Empirically, most large investment-grade companies operate at debt-to-capital ratios of 20–40 %, where WACC is near its minimum. Highly levered companies (e.g., LBO targets) often have lower WACCs on paper but face real risks of covenant breach, credit-rating downgrades, and, in severe cases, bankruptcy.
In normal market conditions, no. WACC is a blend of two positive rates (Re and Rd), so it must be positive. It can become negative only in extreme theoretical cases — for example, if the tax rate exceeds 100 % (which is impossible in practice for standard corporate income tax) or if the cost of debt is negative (which can happen with negative-yielding government bonds, as seen briefly in Europe and Japan). Some highly-rated European utilities did briefly have a WACC below zero when long-term government debt yielded −0.5 % and the equity risk premium was unusually low. But for the vast majority of companies, WACC is a positive number between the after-tax cost of debt and the cost of equity.
The optimal capital structure is the mix of debt and equity that minimises WACC (and therefore maximises firm value) while keeping financial risk at an acceptable level. In the Modigliani–Miller framework with taxes and no distress costs, the optimum is 100 % debt. In the real world, distress costs and agency costs create a trade-off: modest leverage lowers WACC because debt is cheap, but excessive leverage raises both Re and Rd and eventually destroys value. Empirically, the optimum varies by industry: stable, cash-generative industries (utilities, telecoms, REITs) support 40–60 % debt; volatile, asset-light industries (tech, biotech) carry much less. Rather than searching for a single optimum, most companies target a credit rating and let the capital structure follow from that target.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| WACC | Weighted average cost of capital | % |
| E | Market value of equity | currency |
| D | Market value of debt | currency |
| V | Total capital (E+D) | currency |
| Re | Cost of equity | % |
| Rd | Cost of debt | % |
| Tax Rate | Corporate tax rate | % |
What it means
WACC is the weighted average of the cost of equity (Re) and the after‑tax cost of debt (Rd), where weights are based on the market values of equity (E) and debt (D) in the capital structure (V = E + D). It represents the minimum return a company must earn on its existing assets to satisfy its investors. WACC is used as the discount rate in discounted cash flow (DCF) analysis, to evaluate investment projects, and to determine the optimal capital structure. Understanding WACC is critical for corporate finance professionals and investors to assess company value and financial performance.
Worked example
WACC – Two Detailed Examples
Real‑World| Parameter | Value |
|---|---|
| E | 600000 |
| D | 400000 |
| Re (%) | 12 |
| Rd (%) | 6 |
| Tax Rate (%) | 25 |
| Parameter | Value |
|---|---|
| E | 800000 |
| D | 200000 |
| Re | 10 |
| Rd | 5 |
| Tax | 21 |
Common mistakes
- WACC: Weighted average cost of capital – the overall required return for a company.
- E/V: Proportion of equity in the capital structure – market values, not book values.
- D/V: Proportion of debt – similarly market values.
- Re: Cost of equity (e.g., from CAPM).
- Rd: Cost of debt – the yield to maturity on existing debt.
- Tax rate: The corporate tax rate – the tax shield on debt makes its cost lower.
- Assumes: The company maintains a constant capital structure.
Applications
The Weighted Average Cost of Capital (WACC) is the average rate of return a company is expected to pay to all its security holders, weighted by the proportion of each financing source. It is used as the discount rate for project valuation and as a hurdle rate for investment decisions. Corporate finance professionals use WACC to evaluate capital structure, to assess the cost of raising new capital, and to determine whether projects will create shareholder value. By calculating WACC, companies can optimise their debt‑equity mix and minimise the cost of financing. This metric is essential for strategic planning, merger analysis, and performance evaluation.
- Project evaluation and capital budgeting
- Mergers and acquisitions valuation
- Optimal capital structure analysis
- Performance measurement (Economic Value Added)
- Financial modelling and forecasting
Related calculators · Corporate Finance
Recently updated formulas
Suggest an improvement
Found a mistake? Have a better example? Let us know.
You may send up to 3 suggestions per 24 hours.