ABSTRACT Conserving energy resources is crucial for sustaining effort and preventing exhaustion, especially in demanding work environments. Yet, a reliable and valid measure for assessing individuals’ motivation to conserve energy is currently lacking. To fill this gap, we introduce a concise five-item scale, the Conservation of Human Energy Resources Index (CHERI), available in both German (CHERI-G) and English (CHERI-E) versions. In four comprehensive studies (N = 1,814), we evaluated the structure and psychometric properties of both language versions. Our results reveal that the CHERI measures a one-dimensional, homogeneous construct characterized by a high internal consistency (Studies 1, 2, and 4). Our findings also emphasize the CHERI’s sensitivity to change (Study 3) and its meaningful associations with measures from the nomological network of motivation, energy, and effort (Studies 2 and 4). Additionally, we demonstrate the cross-cultural equivalence of the CHERI-G and CHERI-E as well as their equivalence across situational contexts, encompassing both workplace and academic settings (Study 4). Taken together, the present research provides preliminary evidence for the psychometric properties of the CHERI – a measure that can be used to enhance our understanding of energy conservation behaviours and to open new perspectives for advancing research on energy management and recovery.