Artificial Intelligence (AI) is increasingly recognized as a transformative force in education, offering numerous benefits for classroom learning. This study aimed to develop and validate a scale for assessing AI competencies among teachers, focusing on their ability to integrate AI into teaching practices. The study involved 292 secondary-level teachers across six countries and resulted in a 45-item scale organized into nine competence factors. Confirmatory factor analysis confirmed the scale's validity and reliability. Significant differences were noted in AI competencies based on teaching experience and specialty area, while gender did not show significant variance. This AIL scale serves as a valuable tool for educators to self-assess their AI skills, assists professional development institutions, and informs policymakers in designing effective AI training programs. The findings underscore the importance of equipping teachers with the necessary skills to enhance AI integration in educational settings.