Understanding the nuanced components of imagining personal future outcomes is essential for grasping the connections between such cognitive processes and well-being. Despite the existence of future thinking scales, a comprehensive measure capturing the crucial elements of future simulation has been lacking. In two studies, we introduced and validated the Future Simulation Scale (FSS). Employing exploratory factor analyses (Study 1, N = 464) and confirmatory factor analyses (Study 2, N = 724), we identified five factors comprising a total of 31 items: Detailed Imaginations, Positive Expectations, Future Self, Future Social Environment, and Fleeting Imaginations. The FSS exhibited robust reliability and demonstrated convergent and discriminant validity by correlating with existing future thinking measures, as well as measures encompassing well-being, ill-being, and personality traits. Notably, the FSS demonstrated incremental validity, predicting unique variance in transdiagnostic variables beyond other established future thinking scales. The FSS provides a valuable tool for exploring future simulation. While the scale was validated in German, future studies should extend its validation to other languages to enhance its cross-cultural applicability and generalizability. Furthermore, an important future task is to address the lack of criterion validity in terms of correlating our scale with an objective or behavioral measure of future-oriented thinking.