Climate change is a large and global concern. The healthcare sector contributes between 6% and 10% to national carbon emissions in developed countries. Within the healthcare sector, operation rooms are very resource-intensive. A lot of energy, medical products, equipment and pharmaceuticals are required to perform surgery on a daily basis. This report explores methods to calculate the carbon footprint of Dutch operation rooms. Based on these, a tool is developed to calculate total carbon footprint and identify contributing processes. A data collection trial is completed during this development, identifying difficulties in the data collection and calculation process as well as generating some emission results. A tool is designed from the results of this trial. It is based on life cycle analysis, while also including emission factors calculated from sector carbon disclosures. Differences from either one of these carbon emission calculation methods are evaluated and if possible, compared. A final selection of calculation methods for each process is selected and used in the tool. The tool is capable of both internally monitoring carbon emissions over different time periods and comparing emission results with other hospitals. Both these functions can be used to identify emission hotspots, inspire improvements and monitor changes in emissions. Sensitivity of the model to different characterization methods and scope definitions is tested. Ultimately, this tool is aimed to aid in reducing CO2-eq emissions within operation rooms. Recommendations are made to further improve this tool and its data collection procedure.