The textile industry significantly contributes to global greenhouse gas emissions. Companies are thus increasingly forced to calculate carbon footprints at both the corporate (Corporate Carbon Footprint, CCF) and product (Product Carbon Footprint, PCF) level. While both approaches are commonly calculated separately, integrating them into a single analysis provides a more comprehensive understanding of emissions and facilitate targeted reduction measures. This article proposes an approach to calculate the CCF in the textile industry, which integrates a methodology for PCF calculation via mathematical optimization for homogeneous product portfolios. The methodology exploits synergies between PCF and CCF calculations to ensure a consistent and efficient emissions analysis. The practical application of this model is demonstrated through a case study of the German textile SME 3FREUNDE, which is based on primary data from the supply chain and production processes. The results show that an integrated calculation reduces the burden of environmental assessment and provides a solid basis for effective decarbonization strategies at the product and company level. This helps companies meet regulatory requirements and gain a sustainable competitive advantage.