The world is currently experiencing a surge of investment in, and development of, large-scale infrastructural building projects, frequently captured by the term 'megaprojects'. Distinguished by the bulk of their envisioned materiality, the volume of financial capital required to build them, and the complexity of technical, legal, administrative, and political tools needed to bring them into operation, megaprojects do not easily lend themselves to ethnographic inquiry. While in recent years, ethnographic attention to infrastructure has given rise to a burgeoning theoretical apparatus and a growing anthropological subfield in which the various aspects of megaprojects have been analysed, scale as a concept has remained under-theorised. Exploring scale-making ethnographically and unpacking the work that scale does for various actors and publics, the contributions collected in this issue make a theoretical contribution to the anthropology of infrastructure by showing how scale connects the everyday making and the spectacular politics of megaprojects.