<p>Transhipment was an activity that all cargo had to undergo during its journey, but is often absent from discussions and mobility models of Roman transport. The surviving evidence for the cost and time of transferring cargo from the Roman period is often fragmentary and difficult to interpret, but is clear that transhipment was a complex, multistage process. Periods spent in transhipment hubs could cost significant time and money, making transhipment’s inclusion in mobility analyses a necessity. This paper uses a combination of ancient literary and archaeological evidence to explore the cost and time of transhipment in the Roman era. The key stages of the transhipment process are outlined, highlighting that transhipment activities went beyond just the physical handling of cargo. Comparative evidence, in the form of architectural energetics, is also applied to Roman contexts to further explore the duration of transhipment activities. Finally, the importance of considering the volume of cargo undergoing transfer, and the subsequent impact this had on transport flows through transhipment hubs, is highlighted. The paper’s analysis of Roman transhipment activities is used to propose two new methods for incorporating transhipment costs (in both time and money) into future models and discussions of mobility.</p>