Minecraft wiki entry for Map, associated text: Some relevant distances: 128 blocks (8 chunks) is the update radius from a player in the overworld. However, it is half this (64 blocks) in the End and the Nether. Also, 1024 blocks is the minimum Overworld distance from a nether portal, at which players can build another portal and expect to reach a new location in the Nether. This is the distance across a 1:8 map, and also from a 1:16 map's center to its edge.