Developing material flow models of waste and recycling streams can be crucial to determining the inefficiencies of post-consumer plastic packaging recycling systems. Currently, there is no such material flow model of beverage carton packaging waste in The Netherlands because beverage carton management is inherently difficult to measure and calculate. This paper presents a material flow model of beverage carton packaging waste in The Netherlands by calculating potential, collected, sorted, and recycled beverage carton dry weight. The results show that of a potential 60,000 tons of beverage carton material, 47,124 tons are recycled while 12,876 tons end up incinerated. This quantification does not only serve as a starting point for additional research and environmental policy considerations to improve the sustainability of the post-consumer plastic packaging recycling system, but it can also contribute to research in similar settings, leading to a more complete overview of the municipal solid waste recycling system.