The Sustainability ROI Workbook is a free, open-source tool from Sustainability Advantage that helps build a CFO-friendly business case for any sustainability-related project. It integrates guidance from the CFO Leadership Network into a cost-benefit analysis that is framed by a traditional capital expenditure (CapEx) request form. The Excel workbook automatically does the return on investment (ROI) calculations for the project: its payback period, the internal rate of return (IRR), and the net present value (NPV) of its future cash flows. Plus, it includes a Project Appraisal Tool that helps CFOs make better-informed resource allocation decisions, when appraising multiple internal projects competing for limited available capital.