Cost Of Capital Calculator

Weighted average cost of capital (WACC) blends the after-tax cost of debt with the cost of equity, weighted by each component's share of total firm value. The result carries the full formula substitution alongside the WACC figure.

Market value of equity and market value of debt derive the equity weight, E / (E + D), and the debt weight, D / (E + D). Cost of equity is entered directly as a percentage, or derived from the Capital Asset Pricing Model when the exact rate is unknown: Re = Rf + Beta x (Rm - Rf), using the risk-free rate, the equity beta, and the expected market return.

Cost of debt is the effective interest rate the firm pays on its borrowings before any tax deduction. The corporate tax rate multiplies that rate by (1 - Tax Rate) to reflect the tax shield on interest payments, giving the after-tax cost of debt. WACC combines the two: WACC = (E / (E + D)) x Cost of Equity + (D / (E + D)) x Cost of Debt x (1 - Tax Rate).

Results show WACC, the equity and debt weights, and the after-tax cost of debt. A step-by-step view displays the symbolic formula with substituted values and intermediate computations. All inputs accept fractions (3/4), mixed numbers (1 1/2), and scientific notation (1.5e3).

A firm with $700,000 in market value of equity and $300,000 in market value of debt has an equity weight of 700,000 / 1,000,000 = 0.70 and a debt weight of 0.30. With a 12% cost of equity, a 6% cost of debt, and a 25% corporate tax rate, the after-tax cost of debt is 6% x (1 - 0.25) = 4.5%. WACC = (0.70 x 12%) + (0.30 x 4.5%) = 8.4% + 1.35% = 9.75%.

WACC serves as the discount rate for net present value analysis, project evaluation, and enterprise valuation. Below are scenarios where a rapid WACC computation adds direct value.

• Capital budgeting: Discounting projected free cash flows at the firm's WACC determines whether a proposed factory expansion, product launch, or acquisition meets the required return threshold.
• Equity research: Plugging WACC into a discounted cash flow model arrives at an intrinsic share price estimate, comparing it against the current trading price to identify potential mispricings.
• Debt restructuring: Adjusting the market value of debt and the cost of debt fields models how refinancing at a lower interest rate or extending maturity changes the overall cost of capital.
• Leveraged buyout analysis: Modeling the capital structure at various debt-to-equity ratios finds the leverage level that minimizes WACC without pushing the cost of debt into distress territory.
• Startup fundraising: Estimating cost of equity through CAPM with a sector beta and the current risk-free rate, then combining it with anticipated debt terms, presents investors with a credible hurdle rate.
• Academic coursework: Walking through WACC derivations step by step using the formula display reinforces the relationship between capital weights, tax shields, and component costs.
• Annual planning: Recalculating WACC each fiscal year as market conditions shift, using updated equity valuations, prevailing interest rates, and revised tax legislation, keeps investment thresholds current.
• Merger target screening: Comparing the acquirer's WACC against the target's implied return on invested capital determines whether the acquisition creates or destroys shareholder value at the proposed purchase price.

This tool is intended for informational and educational purposes only. It does not provide financial, investment, or tax advice. The amounts and payments shown are estimates and may not reflect actual figures. Results are not guaranteed and may vary based on individual circumstances. Always consult a qualified financial advisor before making any financial decisions.