This chapter discusses the production of demographic measures as a kind of translation. Most demographic data come from surveys or documents produced for administrative purposes, particularly censuses and vital registration. In each case, the production of the document requires that people translate what they understand about the world into demographic categories. As translation, the production of demographic data necessarily entails interpretation; as a translation into a less rich medium, it also involves reduction. The various kinds of demographic data vary considerably in how much they differ from the lived experiences that they translate and partially represent; translations performed mostly by researchers also differ from those performed exclusively by untrained respondents. When done well, there are substantial gains to demographic translation, as a joint result of quantification and aggregation.