Two measures of perceived crowding are used interchangeably by crowding researchers: one assesses how crowded people feel and one assesses how crowded people rate a setting. Two such measures were embedded in questionnaires which were identical except for the crowding measures and were distributed in a dense field setting. Factor analyses indicated that the two crowding measures are conceptually distinct, since the feel crowded item loaded with perceived density, constraint, distraction, and stress, whereas the environmental rating item loaded only with perceived density and general negative affect. The former was also found to be more sensitive to changes in physical density than the latter.