In the present article, we present a systematical review of previous empirical studies that conducted formative assessment interventions to improve student learning. Previous meta-analysis research on the overall effects of formative assessment on student learning has been conclusive, but little has been studied on important features of formative assessment interventions and their differential impacts on student learning in the United States' K-12 education system. Analysis of the identified 126 effect sizes from the selected 33 studies representing 25 research projects that met the inclusion criteria (e.g., included a control condition) revealed an overall small-sized positive effect of formative assessment on student learning (d = 0.29) with benefits for mathematics (d = 0.34), literacy (d = 0.33), and arts (d = 0.29). Further investigation with meta-regression analyses indicated that supporting student-initiated self-assessment (d = 0.61) and providing formal formative assessment evidence (e.g., written feedback on quizzes; d = 0.40) via a medium-cycle length (within or between instructional units; d = 0.52) were found to enhance the effectiveness of formative assessments.