The Learning growth estimator (LGE) is an online tool that provides educationalists with a fast and accurate measure of their teaching impact upon their students. In statistical terms, effect size calculations enable the change between two sets of data to be quantified. The LGE, therefore, provides more detailed insights into the effectiveness of psycho-pedagogical interventions beyond that resulting from basic comparisons, significance tests, and other statistical methods.The LGE compares school and individual results to state/territory values and allows for learning growth to be measured in a standardized manner that is independent of sample size. It produces several interactive reports that are both useful and easily accessed.Underpinned by John Hattie’s principals of Visible Learning, the LGE focuses on providing valuable feedback to educationalists and enables them to quickly assess their teaching effectiveness without the prerequisite of statistical proficiency