Every company has a hurdle rate — the minimum return its projects must beat. That rate is the weighted average cost of capital: a blend of what shareholders demand (cost of equity) and what lenders charge (cost of debt), weighted by how much of each the company uses, with debt adjusted down by the tax shield since interest is deductible. This calculator walks through each piece: enter the market values of equity and debt, the cost of each, and the corporate tax rate, and it computes the weights, the after-tax cost of debt, and the final WACC.

A mid-size manufacturer in Ohio with $800 million in equity at a 12 percent cost and $200 million in debt at 6 percent, facing a 25 percent tax rate, works out to a WACC near 10.5 percent. Any new factory, product line, or acquisition earning less than that destroys shareholder value on paper; anything above it creates value. That is why investment bankers and CFOs argue endlessly over the inputs — especially the cost of equity, which no one can observe directly.

WACC is a model, not a measurement. It assumes a stable capital structure and a single tax rate, and small tweaks to the cost of equity swing the answer. Use it to understand corporate finance decisions and valuation logic, not as investment advice.

With the pre-filled defaults — Market Value of Equity $800,000, Market Value of Debt $200,000, Cost of Equity 12%, Pre-Tax Cost of Debt 6%, Corporate Tax Rate 25% — the WACC Calculator returns Total Capital $1,000,000.00, Equity Weight 0.8000, Debt Weight 0.2000, After-Tax Cost of Debt 4.50%, WACC 10.50%. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.