In the face of growing economic challenges, manufacturing companies are required to adopt development models that take into account both economic information and aspects of social responsibility and environmental protection. More entities are disclosing this data in non-financial, CSR and sustainability reports, which is related to the obligation imposed by the CSRD, published in 2022. ESG reports cover environmental, social and corporate governance criteria, and their descriptive and quantitative indicators are an important tool for assessing the long-term health of an entity. Despite the assumptions of transparency and standardisation, an analysis of manufacturing companies reports shows low comparability, especially in the descriptive parts, which makes it difficult to create rankings. The article proposes simplifying selected environmental non-financial indicators by monetising them — converting them into monetary values based on the concepts of process management and activity-based costing, which link activities to the generation of costs. The aim of the research is to assess the feasibility, purposefulness and usefulness of such an approach and to identify the benefits and limitations of monetising ESG environmental indicators. This original concept may be particularly useful for SME operating simultaneously in the metal and automotive industries in EU, improving the comparability and usefulness of sustainability reports.