CalcWACC Calculator
Calculate the weighted average cost of capital for a firm.
What Is WACC?
WACC — Weighted Average Cost of Capital — is the rate a company must earn on its existing assets to satisfy both its equity investors and its debt holders. It's the hurdle rate: any investment the business makes must return more than its WACC, otherwise it destroys value. If a company's WACC is 8% and a new project only returns 6%, it should not proceed — shareholders and lenders would be better off elsewhere.
WACC is used by analysts, CFOs, and investors to value companies, evaluate acquisitions, and decide whether capital projects make financial sense. It blends the cost of equity (what shareholders demand) and the cost of debt (what lenders charge), weighted by how much of each the company uses, with a tax adjustment because interest payments are tax-deductible.
The Formula
WACC = (E ÷ V) × Re + (D ÷ V) × Rd × (1 − Tc)
- E — Market value of equity
- D — Market value of debt
- V — Total capital (E + D)
- Re — Cost of equity (e.g. from CAPM)
- Rd — Cost of debt (interest rate on borrowings)
- Tc — Corporate tax rate (interest is tax-deductible, which lowers the effective cost of debt)
This calculator uses a simplified version — enter % equity, % debt, cost of equity, and cost of debt directly. Tax adjustment can be applied manually by reducing Rd before entering: Rd after tax = Rd × (1 − tax rate).
Worked Example
Valuing a Mid-Size Manufacturing Company
A company is financed 60% by equity and 40% by debt. The cost of equity (estimated via CAPM) is 10%. The pre-tax cost of debt is 5%, and the corporate tax rate is 25%.
Step 1 — After-tax cost of debt: 5% × (1 − 0.25) = 3.75%
Step 2 — Weight the equity component: 60% × 10% = 6.0%
Step 3 — Weight the debt component: 40% × 3.75% = 1.5%
Step 4 — Add them: WACC = 6.0% + 1.5% = 7.5%
Interpretation: Any project this company invests in must generate returns above 7.5% annually to be value-accretive. A new factory expected to return 9% gets the green light; one expected to return 6% does not.
Common Uses
- DCF valuation: WACC is the discount rate in discounted cash flow models — it converts future free cash flows into a present enterprise value
- Capital budgeting: Comparing a project's internal rate of return (IRR) against WACC to decide whether to invest
- M&A analysis: Estimating the minimum return an acquisition must generate to justify its price
- Performance benchmarking: Companies use WACC to set internal hurdle rates and assess whether business units create or destroy value
Common Mistakes
- Forgetting the tax shield on debt: Interest is tax-deductible, so the effective cost of debt is Rd × (1 − tax rate). Ignoring this overstates WACC and makes projects look less attractive than they are.
- Using book value instead of market value weights: The equity and debt weights should reflect current market values, not historical balance sheet figures. A company whose stock has doubled since IPO has a very different equity weight than its book value suggests.
- Using a single WACC for all projects: WACC reflects the risk of the whole company. A highly leveraged retailer expanding into fintech should use a higher discount rate for the new venture — not its overall corporate WACC.
Pro Tip
To estimate the cost of equity (Re) without a CAPM model, use the dividend growth model: Re = (Next dividend ÷ Current stock price) + expected growth rate. For private companies with no market price, benchmark against public peers in the same industry and adjust for size risk (smaller firms typically carry a 3–5% size premium over large-cap peers).
Frequently Asked Questions
It varies by industry and risk. Capital-light tech companies often have WACCs of 8–12%. Utilities with stable regulated cash flows may have WACCs of 5–7%. Capital-intensive industrials typically sit at 7–10%. The key test is not the absolute number but whether the company's return on invested capital (ROIC) consistently exceeds its WACC — if so, it is creating shareholder value.
Up to a point, adding cheaper debt (which has a tax shield) lowers WACC. But beyond a certain leverage threshold, lenders demand higher interest rates and equity investors demand higher returns to compensate for financial risk — so WACC starts rising again. This is the core trade-off in capital structure theory (Modigliani-Miller with taxes).
WACC is the theoretically correct minimum return. Many companies set their internal hurdle rate higher than WACC — often adding 2–5 percentage points — to create a buffer for uncertainty, forecast errors, and to prioritize only the strongest investments. WACC is the floor; the hurdle rate is the bar projects must actually clear to get funded.
Yes — and often significantly. Rising interest rates increase the cost of debt. A falling stock price increases the cost of equity (lower P/E means investors demand higher earnings yields). Changes in a company's debt ratio shift the weights. For DCF models with multi-year forecasts, some analysts recalculate WACC each year; others use a stable long-run assumption to avoid false precision.