In current LCA studies, the environmental footprint of transport processes is calculated using the weight of the product and the distance travelled. This cannot be considered accurate for returnable packagings that reduce in volume when empty. The weight of the freight as well as the number of trips needed varies and is not taken into account in that calculation. In this research an Excel tool is developed based on an existing CO2 calculation tool created by Partners for Innovation where reduction in volume is taken into account for the environmental calculation of the transportation processes. A factor of reduction of volume is created, which describes to what extent the packaging nests or folds when empty. Next, a calculation is performed that states whether and how many extra trips are needed because of inefficient stacking, or how many trips are saved because of efficient stacking. All of the aforementioned data is used to create a final factor which is in turn multiplied by the amount of ton kilometre in the original calculation. Applying data of fictitious scenarios to the tool shows that the new calculation gives a more precise result regarding CO2 emissions. Furthermore, it shows that nesting of packagings makes a significant positive impact on the CO2 emission as it reduces the number of trips needed to transport the packagings. Lastly, a real-life scenario validates the applicability of the tool in a real situation.