Purpose: In the so-called digital age, there is a basic assumption that digitalization entails rapid and dramatic change in schools, education and society. However, a challenge for educational research is to clarify what digitalization precisely means. This paper aims to develop, test, and validate a digital transformation scale (DTS). More specifically, the aim is to validate digitization, digitalization and digital transformation as hierarchical levels of sociocultural learning in school and education by using cultural-historical activity theory (CHAT) as a framework. Design/methodology/approach: An exploratory factor analysis (EFA), with principal-axis factoring as an extraction method, was used to examine the number of factors underlying the data. Findings: Results show that the three dimensions in the DTS questionnaire explain 68% of the variance and that all dimensions show high internal consistency (a >0.87). This means that the internal structure of the DTS corresponded to the internal structure of the theory. Research limitations/implications: The results show that the internal structure of the DTS corresponded to the internal structure of the theory and may be used quantitatively to analyze digital transformation in school organizations. However, further research is needed in other contexts and larger samples with the use of confirmatory factor analysis to develop knowledge in this area and the use of DTS. Practical implications: This tool and theoretical construction could be used to discuss digital transformation in school and education, both local and in general. Seeing digitalization from a sociocultural perspective makes possible to conceptualize and discuss this as a process ranging from small technology investments on an individual level to digitalization as strategic and organizational development. Originality/value: This DTS can be used quantitatively to study and analyze digital transformation in educational contexts and provides educational researchers with additional tools to articulate what they mean by digitalization.