Districts across the nation are seeking ways to increase efficiency by maintaining, if not improving, educational outcomes using fewer resources. One measure that is sometimes used as a proxy for school district efficiency is an expenditure-to-performance ratio, for example a ratio of per pupil expenditures to student academic performance. This guide shows states and districts how to use publicly available data about district-level expenditures and student academic performance to create six expenditure-to-performance ratios. By illustrating the steps needed to calculate different expenditure-to-performance ratios, the guide also provides states and districts with a straightforward strategy for exploring how conclusions about district efficiency may vary, sometimes substantially, depending on which types of expenditures and which measures of performance are considered. The guide is based on a recent Regional Educational Laboratory (REL) Northeast and Islands project conducted for the Northeast Rural Districts Research Alliance and uses state education department data from one state in the REL Northeast and Islands region. Through the illustration of the steps necessary for calculating expenditure-to-performance ratios, the guide provides states and districts with a set of steps they can use to explore districts’ resource use. Particularly given the descriptive nature of the expenditure-to-performance ratios, the guide also summarizes both the implications for and the limitations of their use.