Methods, apparatus, systems and articles of manufacture to count people in an audience are disclosed. An example method includes analyzing location information collected by a portable device indicative of a location of the portable device. The method also includes analyzing proximity information collected by the portable device indicative of when a person is near the portable device. The example method further includes generating presence information based on (1) the location information and (2) the proximity information, the presence information being indicative of whether the person is present in a media exposure environment associated with a media presentation device.