Regional Educational Laboratory Appalachia researchers developed the Cost-Feasibility Analysis (CFA) Toolkit to help education leaders estimate whether implementing supplemental online programs is affordable given a school or district's available resources. The CFA Toolkit guides users through a four-stage process that yields cost information that can support decision-making about implementing such a program. The toolkit includes guidance, helpful resources, and an Excel-based cost-estimation tool that supports users with planning (stage 1), collecting data (stage 2), estimating program costs (stage 3), and determining the feasibility of implementing the supplemental online program (stage 4).