State Departments of Education recently published the results of their annual assessments of student achievement. Many people want to compare results to previous years and to other schools. Yet, the thought of taking the time to look up formulas in a statistics book or finding a number cruncher to do the work can be a bit daunting. NIFDI's Educational Impact Calculator (EIC) provides an easy, quick, and no-cost alternative. Users enter aggregate data (e.g. percentage of students at benchmark, means and standard deviations or the percentile rank of the average student) and the EIC instantly calculates the effect size, improvement index, and probability results that would occur by chance. Click here to get to the EIC. The website contains numerous examples of questions the calculator can answer and its use. It also has explanations of the input data and output statistics and links to a technical report that provides complete details on the underlying statistical formulas and research designs.