Minecraft chunk calculator
Type coordinates from the F3 screen and see the chunk, the position inside it and the region file.
Chunk -8, 28
Position inside the chunk 5, 64, 8
The chunk covers X -128 to -113 and Z 448 to 463
Region -1, 0, file r.-1.0.mca
Chunks and regions
The world is saved in chunks. Plugins like Chunky and commands like /forceload work in chunk coordinates, and the files on disk are grouped into regions. Knowing which chunk a block is in tells you which file holds it and where a chunk border lies.
Questions
How big is a chunk?
A chunk is 16 by 16 blocks and as tall as the world. A region is 32 by 32 chunks, which is 512 by 512 blocks, saved in one file named r.x.z.mca in the region folder.
Why are negative coordinates tricky?
Chunk numbers are counted by rounding down, so block -1 is in chunk -1, not chunk 0. The tool does that for you.
What is the slime chunk or spawn chunk trick?
Both depend on the chunk coordinates this tool gives. The world spawn keeps a square of chunks loaded around it, and slime chunks are picked from the world seed, which you can look up with a seed map.
Which file do I delete to reset one area?
Stop the server, then remove or replace the region file shown under "Region file". Minecraft makes the area again the next time it is visited. Keep a backup first.
Related guides
More free tools
Ready to run it?
1 GB is free forever, with no card and no ads. Add memory when you need it.
Make a free server