The notion of a personal space surrounding one's ego-center is time-honored. However, few attempts have been made to measure the shape of this space. With increasing use of virtual environments, the question has arisen if real-world aspects, such as gender-effects or the shape of personal space, translate to virtual setups. We conducted two experiments, one with real people matched according to body height and level of acquaintance in a large laboratory setting, and one where subjects faced a virtual character, likewise matched to their body height. The first experiment also used a mannequin in place of the second human observer. The second experiment additionally manipulated the perspective of the subject to compare estimates of interpersonal distance between an egocentric and an allocentric perspective (in third-person view). Subjects approached (or were approached) from different angles until a comfortable distance for conversation with a stranger was reached (stop-distance task). Personal space turned out to be rather circular with a radius of about 1 m. Male pairs kept larger distances from one another than female or mixed-gender pairs. All subjects assumed larger distances to the mannequin compared to the real observer. Very comparable distances were preferred to the avatar in the virtual environment. Also, it did not matter whether the subject was engaged in active approach, was approached, or merely adjusted the distance between two avatars. Implications for theories of personal space are discussed.