The digital literacy of older adults for widespread inclusion in a globalised world requires tools that provide accurate, personalised, and purpose-driven information aligned with the goals of successful ageing. Although there is evidence of interest in rubrics as an assessment tool due to their ability to offer detailed and contextualised information, there are very few examples of their use in measuring digital competencies tailored to active ageing situations. The study presented here aims to validate a rubric-based assessment scale, using the DigComp model as a reference and adapting it to the context of active ageing. The scale was developed using the Delphi method and an initial version was refined through expert consultation. Following pilot testing and criterion-based validation, the final version was applied to a sample of 178 participants aged over 65. Validity tests and model fit to the data were found to be acceptable. The results yielded sustainable findings within the scientific literature, providing external validity for the measurement tool. This study contributes a valuable resource both for the development of training and support programmes aimed at promoting the digital inclusion of older adults, and for the assessment of their digital competence for research purposes.