Anthropogenic greenhouse gas emissions need to be cut to limit climate change. Thus, universities, in the same way as citizens and companies, are starting to raise awareness about this issue and to take action to reduce their carbon footprint. Centrale Nantes, a French “Grande école”, initiated a low carbon transition with the calculation of the 2018 carbon footprint of the university. This report presents an individual carbon footprint estimator developed within the scope of the university, based on the new open-source French national simulator called “Nos Gestes Climat” proposed by ABC (Association Bilan Carbone (Association for the implementation of Carbon footprint assessment)) and ADEME (French Environment and Energy Management Agency). Development context and important features of the national version are described. Then, to meet university user’s expectations, feedback from a panel of testers has been collected in order to guide the declination development and promote good practices ensuring user engagement. The transparency of the data model, the accurate explanations, the variety of actions have been found to be key success factors for the development and the adoption of such a simulator. Results also suggested that users are keen to involve themselves in the university initiative to reach carbon neutrality.