Waste materials and industrial by-products are increasingly used in the production of cement clinker and cement, serving as secondary fuels, secondary raw materials, and supplementary cementitious materials. As these waste-derived materials are partially or fully incorporated into the product, they are technically recycled. Consequently, a certain proportion of the cement consists of recycled materials. This paper presents a method to calculate this recycled content in cement not only based on mass streams, but also based on valuable chemical components and compares the results for both calculation methods in the course of a case study of two Austrian cement plants. It is demonstrated that one metric ton of cement consists of 365 kg and 387 kg of secondary materials, respectively. This results in an average recycled content of 37.6 %. In addition, the contribution of primary and secondary materials to the heavy metal content of cement is assessed.