Currently, masses of studies on mathematics learning getting to know have been discovered in numerous literatures supported by the use of blended learning model. This meta-analysis study aims at determining the overall effect of using blended learning. This study analyses 36 effect sizes from ERIC documents, Google scholar, and repositories from 2012 to 2021, overlaying a total of 1255 students. To support calculation accuracy, JASP software is used. effect size is decided with an appropriate confidence level of 95%. This study found that the effect size generated using the random effects model was 1.269 (Very High Effect). This finding shows that on average, students in Indonesia who use blended learning effectively can improve their math skills. This study finds out how far the effect of the use of blended learning on students' mathematical abilities and provides information for the use of the next blended learning model.