The distance that an AirTag can reach depends on the kind of method that is used. That is, whether it’s using a Bluetooth connection or Apple’s own precision tracker which is embedded in the “Find My App” settings. Apple is yet to reveal (and may not), the actual distance that the AirTag may cover. Here’s an estimation regardless.
If you’re using Bluetooth to connect to an iPhone during the initial setup process, the iPhone needs to be within a range of 33 feet to connect to the Bluetooth device, according to Apple. Therefore, regardless of the actual range of an AirTag, the operating distance for Bluetooth is 10 meters.
However, there are additional factors that can limit or extend the distance of a Bluetooth connection, like the kind of device the AirTag is used on.
When using other means, ie the Find My system, the network can be used to find the general area in which the AirTag is located, making it possible to initially locate a lost or missing item from great distances. Then, when you’re within range of the AirTag, the Bluetooth can take over to help you locate your missing item.