The regarded gravel plant produces round and crushed grain (square grain). The main customer of the plant is the adjacent asphalt mixing plant, which uses only edge grains as asphalt aggregate. This thesis investigates the production costs of both round and square grains and conducts direct comparison. Production costs representing manufacturing costs of the products will be obtained via calculation. The first part of the thesis introduces the process. A detailed description of the process and the individual parts of the plant are mapped using a flow chart of the gravel processing plant. The gravel processing plant is subdivided into three areas, round grain production, square grain production, and back-grinding. A mass balance based on sampling data provided an estimator for the hourly production volume of each product. The second part comprises a review of the costs sourced from financial accounting in the form of invoices. These invoices are listed and categorised. Subsequently, the costs were assigned to the individual positions of the gravel processing plant. Direct costs are allocated directly, overheads using a billing key. In the third part of the thesis, the production costs of the products are converted to Euro per tonne basis with remarks on the improvement potential for the treatment process.