Minecraft wiki entry for Mapping, associated text: To keep zoom-level 1 maps from overlapping, ensure that each is built from a zoom-level zero with x- and z-coordinates that are multiples of 256. To keep zoom-level 2 maps from overlapping, build them from zoom-level 0 maps with x/z coordinates that are multiples of 512. Zoom-level 3 maps should only be crafted from zoom-level 0 maps centered on x/z coordinates that are multiples of 1024; and zoom-level 4 maps should be crafted from zoom-level 0 maps with x/z coordinates that are multiples of 2048.