Block coordinates
Chunk 16×16 blocks
A chunk is the 16×16 column of blocks the world generates and saves as one unit, from bedrock to the build limit.
Region file 32×32 chunks
Each region file bundles a 32×32 grid of chunks into one .mca on disk — handy to know when you only want to back up or delete one area of a world.
Overworld and Nether 8:1 scale
Notice the round-trip Z landed on -1296, not the original -1290 — that few-block drift is normal, not a bug. See the explanation below.
X and Z divide by 8 going into the Nether and multiply by 8 coming back out; Y never changes either direction. Build the destination portal yourself at the converted spot rather than trusting auto-generation — for the full search-range picture, see the dedicated Nether Portal Calculator on this site.
Distance and heading between two points
North-East, 1124.8 blocks across, up 46
How Minecraft coordinates split into chunks and regions
Every block sits inside a 16×16 column called a chunk, and the game addresses chunks the same way it addresses blocks — by dividing the block coordinate by 16 and keeping only the whole-number part. Thirty-two of those chunks in each direction bundle together into a region, saved on disk as a single .mca file, so a region covers a 512×512-block square. Height never enters this math: a chunk is a full vertical column from the bottom of the world to the build limit, so Y is irrelevant to both the chunk and region calculations — only X and Z matter.
The tricky part is negative coordinates. Minecraft always rounds toward negative infinity (a "floor" division, equivalent to the bit-shift the game uses internally), not toward zero the way a naive integer division does in most programming languages. Block Z = -1290 floor-divides to chunk Z = -81, not -80, because -1290 ÷ 16 = -80.625 and flooring that goes down to -81. The offset inside the chunk follows the same rule: it is always reported as a positive number from 0-15, computed as a positive modulo rather than whatever sign a plain remainder operator would give.
Converting between the Overworld and the Nether
The Nether is built at one-eighth scale, so one block of Nether travel covers eight blocks in the Overworld. Going into the Nether, divide X and Z by 8 (floor division again, same negative-rounding rule as chunks); coming back out, multiply by 8. Y is copied across unchanged in both directions — the ratio only applies to the horizontal plane.
Because entering the Nether floors the division, some precision is thrown away, and multiplying back out cannot recover it. That is why a round trip Overworld → Nether → Overworld can land a handful of blocks away from where you started — this is expected floor-division drift, not an error in the math. For a reliable link between two portals, do not rely on auto-generation: convert your intended destination coordinates and build the receiving portal by hand at that exact spot. The Nether Portal Calculator tool on this site covers the full search-range visualization if you want to see exactly how the game finds (or fails to find) a portal to link to.
| Conversion | Formula | Example |
|---|---|---|
| Block to chunk | floor(block / 16) | -1290 → -81 |
| Block to region | floor(block / 512) | -1290 → -3 |
Negative-coordinate math uses floor division (rounds toward negative infinity) throughout, matching how the game actually computes chunk, region, and Nether coordinates — never simple truncation.
Nether coordinates?
Nether portal coordinates to prevent cross-linking?
