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In recent years, a growing literature has measured the impact of education interventions in low- and middle-income countries on both access and learning outcomes. But interpretation of those effect sizes as large or small tends to rely on benchmarks developed by a psychologist in the United States in the 1960s. In this paper, we demonstrate the distribution of standardized effect sizes on learning and access from hundreds of studies from low- and middle-income countries. We identify a median effect size of 0.10 standard deviations on learning and 0.06 standard deviations on access. Effect sizes are similar for randomized controlled trials and for quasi-experimental studies. They are much larger for small-scale studies than for large-scale studies. Understanding the distribution of existing effects can help researchers and policymakers to situate new findings within the distribution of current knowledge.