Some passive RFID tags can only be read from a distance of a few inches, but most can be read from around three feet. Higher frequency RF waves can be detected from farther away than low frequency ones: Some high frequency RFID tags can even be read from one hundred feet away. The trade-off is that high frequency waves are more easily disrupted, which is why most passive RFID tags stick with a reliable range of three feet.
Since active RFID tags are battery-powered, their signal carries farther. Most active tag signals can be detected from a maximum of three hundred feet, though some go as far as six hundred feet.
While the signals of certain RFID tags can be extended with special antenna, no RFID signal can get past the technology's hard limits, which are around one hundred feet for passive RFID tags and around six hundred feet for active RFID tags.