WACC Calculator
Calculate the weighted average cost of capital (WACC) from the cost and market value of equity and debt, plus a tax rate. Get the blended WACC, the after-tax cost of debt and tax shield, and a full equity-vs-debt capital-structure breakdown.
Input
Often estimated with CAPM.
Pre-tax average interest rate on the company's debt.
Marginal corporate tax rate — interest is tax-deductible, equity returns are not.
Output
| Metric | Value |
|---|---|
| No data yet | |
| Component | Market Value | Weight | Cost (after-tax for debt) | Contribution to WACC |
|---|---|---|---|---|
| No data yet | ||||
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/wacc-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"costOfEquity": "12",
"marketValueEquity": "5000000",
"costOfDebt": "6",
"marketValueDebt": "2000000",
"taxRate": "25",
"currency": "USD"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `wacc-calculator` tool (WACC Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/wacc-calculator/"
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sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
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<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
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Guides
What is WACC?
Weighted average cost of capital (WACC) is the blended rate a company pays, on average, to finance its assets — combining the return equity investors expect with the interest it pays on debt, weighted by how much of each it uses. It's the standard discount rate for NPV/IRR analysis and capital-budgeting decisions: a project only creates value if its expected return exceeds the WACC.
WACC = (E/V × cost of equity) + (D/V × cost of debt × (1 − tax rate))
where E is the market value of equity, D is the market value of debt, and V = E + D is total capital.
How this tool works
- Enter the cost of equity (often estimated with CAPM) and the market value of equity.
- Enter the cost of debt — the average pre-tax interest rate on the company's debt — and the market value of debt.
- Enter the tax rate: interest is tax-deductible, so debt's true cost to the company is lower than its stated rate.
- The Summary shows total capital, the after-tax cost of debt, the tax shield, the blended WACC, and a qualitative assessment. The Capital Structure Breakdown shows each component's market value, weight, cost, and contribution to the overall WACC — copyable and downloadable as CSV.
Why the tax adjustment matters
Debt's after-tax cost is cost of debt × (1 − tax rate) — a company paying 6% interest at a 25% tax rate effectively pays only 4.5%, because the interest expense reduces taxable income. Equity has no equivalent shield: dividends and buybacks aren't tax-deductible, so the full cost of equity always carries through.
Common uses
- Choosing the discount rate for an NPV or DCF valuation
- Evaluating whether a project or acquisition clears the company's cost of capital
- Comparing how a shift in capital structure (more debt vs. more equity) would move the blended rate
- Benchmarking a company's financing cost against peers
Privacy
This tool runs entirely in your browser. Your numbers are never uploaded to a server.
Is this the same WACC analysts publish for public companies?
Not exactly — published WACC figures often use more refined inputs (CAPM with a specific beta and risk-free rate, a multi-year average cost of debt, marginal vs. effective tax rate). This tool applies the standard formula to whatever equity/debt costs and values you provide, so it's only as precise as those inputs.