This report provides a comprehensive analysis of AGL Energy Ltd's corporate finance, focusing on the calculation of its Weighted Average Cost of Capital (WACC) and the evaluation of its capital structure. The report begins with an introduction to corporate finance, emphasizing the importance of maximizing shareholder wealth through effective financial planning and strategic implementation. It then provides an overview of AGL Energy Ltd, an Australian energy company, and proceeds to calculate its WACC using the Capital Asset Pricing Model (CAPM) and dividend capitalization methods to determine the cost of equity and the cost of debt. Gearing ratios are also calculated to assess the company's leverage and financial risk. The report analyzes the findings in the context of capital structure theory, including the Modigliani-Miller (M&M) theory, and concludes with recommendations to the board on optimizing the company's capital structure to minimize its cost of capital and improve financial performance. The report uses financial data from 2017 to 2019 to support its analysis and draws on various academic and industry sources to provide context and validation. The report concludes that AGL Energy should increase its use of debt to reduce its WACC.