Cost of Capital Calculator - WACC and Financing Mix

Cost of capital is the blended return that providers of equity, debt, and preferred stock require. In valuation it is the discount rate for free cash flow to the firm. In capital budgeting it is the hurdle rate a project should beat if its risk resembles the firm. The cost of capital calculator estimates weighted average cost of capital, or WACC. Equity cost comes from the capital asset pricing model: risk-free rate plus beta times market risk premium. Debt cost is the pretax yield reduced by the tax shield Rd × (1 − T). Preferred stock, if you enter a market value, is weighted at its stated cost. Weights use the market values you type, not book values. Let E, D, and P be market values of equity, debt, and preferred, and let V = E + D + P. Then WACC = (E/V) Re + (D/V) Rd (1 − T) + (P/V) Rp. Re = rf + β × MRP, with rf, Rd, Rp, and the market premium entered as percents (4 means 4%). The tax rate is also a percent and is divided by 100 only in the shield term. Preferred value and preferred cost may be left blank; they are treated as zero and drop out of V. The headline result is WACC as a percent. The supporting figure is total capital V in dollars so you can confirm the weights. Analysts use WACC to discount unlevered cash flows, to compare a leveraged recap with an all-equity plan, and to sanity-check a private-company hurdle rate. Because equity is usually costlier than after-tax debt, adding cheap debt can lower WACC until distress risk raises both Rd and beta. This worksheet does not increase beta as leverage rises, so an aggressive debt mix can understate WACC. Use market values: a cheap historical coupon is not the current cost of debt if yields have moved. For equity, beta should match the firm’s operating risk and, ideally, its target leverage. Inputs are easy to mix up. A market premium of 5% plus a 4% risk-free rate and beta of 1.1 produces Re = 9.5%, not 9.5 percentage points on top of something else. Do not enter decimal rates such as 0.06 unless you truly mean 0.06%. The cost of capital calculator treats component costs as percent numbers. Preferred dividends are not tax deductible here, which is why Rp is not shielded. Short-term debt, leases, and convertible notes are omitted unless you fold them into the debt value and pretax cost yourself. WACC is not a guarantee of investor returns and not the right discount rate for a project whose risk differs from the firm. Country risk, size premia, and flotation costs are outside the formula. Recalculate when the risk-free rate, credit spread, or capital structure changes. For a levered-equity DCF, use cost of equity rather than WACC. Keep a source note next to each input (Treasury yield, beta vendor, tax rate) so a reviewer can challenge the 7.60% rather than the algebra. The cost of capital calculator is there to make the weighted average checkable, not to hide a pile of silent assumptions inside a single discount rate.