Cost of Capital Calculator

Written by Great Medico

Updated September 25, 2026 •2 min read

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A result from Cost of Capital Calculator becomes more meaningful when the source numbers and formula stay visible. That makes it easier to reproduce the calculation instead of relying on an unexplained figure.

What this calculator does

Cost of Capital Calculator combines the entered cost of equity and after-tax cost of debt using their capital weights. It works from equity weight, cost of equity, debt weight, pre-tax cost of debt, and tax rate. For Cost of Capital Calculator, because no outside market data is inserted, the result stays tied to the exact assumptions visible on the page.

How to use it

Use the form to supply Equity weight, Cost of equity, Debt weight, Pre-tax cost of debt, and Tax rate. For Cost of Capital Calculator, enter percentage or rate fields on the scale displayed by the form rather than converting them to an unstated format. Before calculating, recheck Equity weight, Cost of equity, Debt weight against the source numbers you intend to analyze.

How the calculation works

WACC = equity weight × cost of equity + debt weight × pre-tax cost of debt × (1 − tax rate). The Cost of Capital Calculator result follows the stated equation and the form values relevant to that calculation. For Cost of Capital Calculator, the result is only meaningful for the exact values supplied, so input errors should be corrected before interpretation.

Example

With 60% equity at 10%, 40% debt at 6%, and a 25% tax rate, WACC is 7.8%. The Cost of Capital Calculator example is a math check only; your result should come from the values entered on the form.

How to interpret the result

The result is a blended financing-rate estimate often used as a hurdle or discount-rate reference when the project has risk similar to the firm’s capital base. For a clean comparison with Cost of Capital Calculator, keep the displayed input definitions and measurement basis consistent across scenarios.

Limitations and notes

The calculator assumes the entered weights and component costs are appropriate and stable. It does not estimate market values, preferred stock, issuance costs, changing leverage, country risk, or a project-specific risk adjustment. Recalculate Cost of Capital Calculator when the source values entered on the form change materially.