The article explores one of the most important tropes in twentieth-century urban planning discourses: the "human scale." Drawing from printed and archival sources from Sweden and Germany, it demonstrates how, in the 1930s and 1940s, this metaphor provided urban planning experts—architects, social scientists, and housing reformers—with an important epistemological framework: it helped them define the social in technical terms and thus substantiated ideas about the malleability of society by means of spatial intervention. In practice, in both countries, the human scale informed schemes for a decentralization and delimitation of the urban fabric. Neighborhood units or settlement cells, as they were called in Germany, were to correlate with—and thus reinforce—"organic" social entities: primary groups like families and small communities of neighbors. Planners were attempting to re-calibrate urban agglomerations to what they perceived as measurable, natural social entities. They were compiling anthropometric data, claiming that quantifiable dimensions like the "pram-pushing distance" were ideal criteria in delimiting the built environment. Such data even crossed borders between political systems as different as those of the Nazi-"Third Reich" and the social-democratic "People’s Home" in Sweden. Thus, notwithstanding the great differences regarding its political implication, analyzing the semantics of humanization in urban planning helps explain transnational efforts to "engineer" the social to overcome the disorder attributed to modernity itself.