X-Road® is open-source software and ecosystem solution that provides unified and secure data exchange between organisations. The basic idea of X-Road is that members of an ecosystem exchange data through access points that implement the same technical specifications. X-Road is a digital public good verified by the Digital Public Goods Alliance, and it’s released under the MIT open source license and is available free of charge. X-Road is used as a national data exchange solution in Estonia, Finland, Iceland, and many other countries around the world. To better understand the direct and tangible environmental impacts of the use of X-Road, the current emissions profile across X-Road’s operations and services was assessed by a research project. As a result, an emissions calculator to assess X-Road’s environmental footprint was built. The calculator gives a clear picture of the total carbon footprint of X-Road, as well as its individual components. In my talk, I’m going to give an overview of X-Road first. Then, I’m going to discuss the research project, its different phases and deliverables. The main scope of the presentation is to discuss how to evaluate the environmental footprint of an open-source software and what the key elements are that affect the result.