This document discusses estimating the weighted average cost of capital (WACC) for a company. It covers the three main components needed to calculate WACC: 1) the cost of equity, 2) the after-tax cost of debt, and 3) the target capital structure weights. For the cost of equity, it describes the capital asset pricing model (CAPM) and how to estimate beta and market risk premium. Historical data and industry unlevered betas are used to improve estimates. The example shows how WACC is calculated for Home Depot using CAPM cost of equity and after-tax cost of debt weighted by targets.