The representation of the distribution of knowledge guides information gathering, help seeking, and communication. The research aimed to explore adults’ and 4-year-olds’ representation of the distribution of common (conventional and procedural) knowledge and expert knowledge associated with five occupations in their community. In addition, we examined estimates of occupation-related everyday (non-expert) knowledge. Both groups estimated that common knowledge is more widely held than expert knowledge, with everyday knowledge in between. For adults, but not children, the distribution of expert knowledge was correlated with estimates of the proportion of people in each occupation.