<p>Augmented reality (AR) continues to demonstrate its impact on education. Despite the increasing interest in AR as a pedagogical tool and the evidence gathered from literature reviews, there has been limited information on how AR may improve the mathematics achievement of K-12 students. This study aims to synthesize the effects of AR use on the mathematics achievement of K-12 students. In this study, we conducted a meta-analysis of 22 experimental studies with 25 different samples published before July 2023. The findings revealed a medium effect size of AR use on the mathematics achievement of K-12 students (g = 0.765), indicating its positive influence. We further conducted moderator analysis to investigate variations in this impact, considering three research characteristics variables (mathematics domain, educational level, and treatment duration), and two AR features variables (connectivity and integration of virtual objects). The results of the moderator analysis showed that the integration of virtual objects variable had a significant moderating effect, implying the effect of AR on the mathematics achievement of K-12 students may vary depending on the integration of virtual objects. However, the effects of other moderating variables were not significant. We provided further implications for future research and practice.</p>