The objective of this work was to propose an environmental scoring tool for food packaging based on the assessment of three key pillars of packaging sustainability: Materials, Functionality and Post-Usage fate. A participatory process involving relevant food-packaging experts and end users was applied to define the relevant criteria for each pillar. Each criterion was translated into a question for users, and the answers are converted into a score between 0 (worst option) and 1 (best option) per pillar. For the Materials pillar, two scores were computed from a streamlined calculation of resource (CEENE) and carbon footprints (IPCC) while for the Functionality and Post-Usage pillars, scores were computed from Yes/No answers provided by the users. A fourth pillar considers the potential risk of long-term environmental pollution. Then, the packaging options for the same food are ranked according to the Borda voting rule, considering the individual rankings obtained for the various pillars. The proposed methodology was applied to three commercial (milk and sugar) and non-commercial (strawberry) packaging case studies. The obtained ranking is discussed with respect to current knowledge in the field. The provided methodology is easy to understand, science based, and combines quantitative and qualitative assessments. The developed tool could be handled by non-experts in environmental sciences such as food manufacturers, packaging converters and policy makers. The resulting indicators provide answers to user concerns regarding the environmental impacts of food packaging and guide their choice of the most sustainable option. The proposed scoring method considers the functionality of the packaging with respect to preserving food and reducing food waste, which is rarely considered in packaging environmental assessments.