From how far away can an RFID tag be read?
The read range for an RFID tag depends on many factors. First, if the tag is passive it will have a shorter read range (typically between 1cm to 4m on average); active tags can be read from a much greater distance (e.g. upwards of 20m). Secondly, the materiality of the tagged object has an affect on the read range. For example, a tag attached to a metal object may have a much shorter read range than a tag attached to a plastic object. The size and power of the RFID reader’s antenna also has a large impact, though it is practically impossible to build an antenna which will read tags at a distance greater than ten times the standard read range.
