This paper analyses the environmental impact of reusable shipping packaging compared to single-use alternatives in e-commerce, focusing on carbon emissions. It takes into account the growth of online retail due to the Covid-19 pandemic. It evaluates a reusable polypropylene (PP) box and a reusable shipping bag, comparing them with single-use low-density polyethylene (LDPE) bags. The reusable shipping bag showed advantages after a few cycles, depending on the use of recycled materials, while the PP box required 32–81 cycles to break even in terms of CO2 emissions. The study’s carbon footprint comparison shows that reusable packaging is environmentally advantageous if it is reused often enough. To achieve this, however, political and economic incentives seem necessary.