The Impact Calculator is a tool designed to help Product Managers assess the potential impact of various initiatives on key performance indicators (KPIs) by evaluating the scope and magnitude of proposed changes. It guides users through a process of entering baseline metrics for a project, estimating the number of users affected by a change, and predicting conversion rates post-intervention. This allows for comparison of multiple initiatives to determine which holds the most promise for improving KPIs, facilitating better decision-making on project prioritization. By enabling quick and repeatable opportunity sizing, the tool helps in building a data-driven roadmap and encourages revisiting assumptions to refine product strategies over time.