Legal regulations and industry standards require organizations to measure and maintain a specified IT-security level. Although several IT-security metrics approaches have been developed, a methodology for automatically generating ISO 27001-based IT-security metrics based on concrete organization-specific control implementation knowledge is missing. Based on the security ontology by Fenz et al., including information security domain knowledge and the necessary structures to incorporate organization-specific facts into the ontology, this paper proposes a methodology for automatically generating ISO 27001-based IT-security metrics. The conducted validation has shown that the research results are a first step towards increasing the degree of automation in the field of IT-security metrics. Using the introduced methodology, organizations are enabled to evaluate their compliance with information security standards, and to evaluate control implementations’ effectiveness at the same time.