This research aims to test the validity and reliability of mathematics self-efficacy using Microsoft Excel and Winsteps at the High School (SMA) level. The method used in this research is a quantitative survey research method. The subjects in this study were students of class XI in one of the public high schools in the city of Bekasi and private high schools in the city of East Jakarta which opened 122 students. The results of this study indicate that the item and person are valid and the self-efficacy of the mathematical instrument is reliable.