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WACC Calculator

Calculate weighted average cost of capital from market-value weights, CAPM cost of equity and a blended after-tax cost of debt, with Hamada beta relevering.

Cost of equity

Cost of debt

Columns: name, amount, rate %

Total debt $350.00 · blended pre-tax rate 6.63%

8.67%
WACC
10.52%
Cost of equity
5.24%
After-tax cost of debt
1.150
Levered beta

Capital structure and weighted contributions

Each capital component, its weight and its contribution to WACC
ComponentMarket valueWeightCostContribution
Equity$650.0065.00%10.52%6.84%
Debt (after tax)$350.0035.00%5.24%1.83%
Total capital$1,000.00100.00%—8.67%

WACC = (E ÷ V) × Re + (D ÷ V) × Rd × (1 − tax rate). Cost of equity uses CAPM, Re = risk-free + β × equity risk premium, plus any size and country premiums you enter. The Hamada relevering step is βL = βU × (1 + (1 − tax) × D/E). With no equity and no debt entered there is no capital base to weight, so every figure shows an em dash instead of dividing. Estimates for analysis only, not investment advice.

What is the WACC Calculator?

The ByteTools WACC Calculator works out the weighted average cost of capital a business uses as its discount rate.

  • Full formula: (E ÷ V) × Re + (D ÷ V) × Rd × (1 − tax rate)
  • CAPM cost of equity with optional size and country risk premiums
  • Hamada unlevering and relevering from a comparable company's beta
  • Multi-tranche debt table producing a weighted blended pre-tax rate
  • Component table showing each weight, cost and contribution to WACC
  • Shows an em dash instead of dividing when there is no capital base

How to use the WACC Calculator

  1. 1

    Enter the market value of equity, the corporate tax rate and pick your currency.

  2. 2

    Choose CAPM and fill in the risk-free rate, equity risk premium and beta, or switch to entering a cost of equity directly.

  3. 3

    For beta, either type your levered beta or pick Hamada to unlever a peer's beta and relever it at your own debt/equity ratio.

  4. 4

    Add each debt tranche with its amount and rate to get a blended pre-tax cost of debt, or untick the box and enter one figure.

  5. 5

    Read WACC, cost of equity, after-tax cost of debt and the component contribution table.

About the WACC Calculator

The ByteTools WACC Calculator works out the weighted average cost of capital a business uses as its discount rate. Enter the market value of equity and debt, a corporate tax rate, and a cost of equity from CAPM, and it returns WACC along with each component's weight, cost and contribution in a single table.

It is built for analysts building a DCF, founders pricing a funding round and finance students checking homework. You can enter a levered beta directly or unlever a comparable company's beta and relever it at your own capital structure, and you can blend several debt tranches into one pre-tax rate rather than guessing an average.

Every figure is calculated locally in your browser — nothing is uploaded, stored or sent to a server, so it is safe to use with real deal numbers. Results are estimates for analysis and are not investment advice.

Frequently asked questions

How do you calculate WACC?

WACC is the equity weight times the cost of equity plus the debt weight times the after-tax cost of debt: (E ÷ V) × Re + (D ÷ V) × Rd × (1 − tax rate), where V is equity plus debt. With 60% equity at 12%, 40% debt at 8% and a 30% tax rate, WACC is 0.6 × 12 + 0.4 × 8 × 0.7 = 9.44%.

Should I use market values or book values for the weights?

Market values are the standard choice because WACC is meant to reflect what investors require today, not what was recorded historically. Equity is usually share price times shares outstanding. Book values are only a reasonable stand-in for debt, which rarely trades far from par.

Why is the cost of debt multiplied by one minus the tax rate?

Interest is generally tax deductible, so a company paying 8% on its debt only bears 8% × (1 − 30%) = 5.6% after the tax shield. Equity dividends are not deductible, which is why the cost of equity is never adjusted this way.

What is the Hamada equation used for?

It converts a beta between capital structures. Unlevering strips a comparable company's financial leverage out of its beta, and relevering puts your own leverage back in: βL = βU × (1 + (1 − tax) × D/E). It matters because a peer with different debt is not directly comparable.

Why is my WACC lower than my cost of equity?

Debt is almost always cheaper than equity, partly because lenders rank ahead of shareholders and partly because interest is tax deductible. Adding debt pulls the weighted average below the cost of equity, though only up to the point where the extra risk starts pushing both costs up.

Are my figures kept private?

Yes. Every calculation runs entirely inside your browser and nothing is transmitted or saved, so confidential valuation inputs never leave your device.

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