A device determines, based on location verification data that has been received, that the device is indoors at a first geographic location. The device determines a base measured barometric pressure, and an initial floor that the device is located on in a structure that includes the first geographic location. The device determines an adjusted measured barometric pressure for a second geographic location based on a second measured barometric pressure for the second geographic location and one or more reference barometric pressures that are associated with a reference location. The device determines an altitude for the second geographic location based on the base measured barometric pressure and the adjusted measured barometric pressures. The device causes a server to predict a floor that the device is located on at the second geographic location and to provide floor data that identifies the floor to an interface that is accessible to the device.