Minecraft Region Finder

Enter block or chunk coordinates to find the .mca region file that holds them, with the exact path for the Overworld, Nether and End on vanilla, Paper and 26.1+ worlds. Paste a file name to go the other way and see the area it covers.

The X and Z you see on the F3 screen or use with /tp. Paste the whole "XYZ:" or "Block:" line into X and it fills every field.

XYZ

Folder

Vanilla, Forge, Fabric, NeoForge (before 26.1): One world folder. The Nether and End sit inside it as DIM-1 and DIM1. Folder is the level-name from server.properties. Not sure which layout you have? Look for a dimensions folder inside the world (26.1+) or a world_nether folder next to the server jar (Paper, Spigot).

Region file

r.0.0.mca

Overworld, classic layout, chunk 0, 0 (block 0, 0)

Terrainworld/region/r.0.0.mca

Entitiesworld/entities/r.0.0.mca1.17+

POIworld/poi/r.0.0.mca1.14+

Paths are relative to the server folder. Delete, copy or restore all three files together so entities and villager data stay in step with the terrain.

In the region: local chunk 0, 0 (index 0 of 1024)
Header entry: location at byte 0, timestamp at byte 4096
Blocks: X 0 to 15, Z 0 to 15, all Y levels
Block in chunk: 0, 0

Chunks: X 0 to 31, Z 0 to 31 (1,024 chunks)
Blocks: X 0 to 511, Z 0 to 511
Height: Y -64 to 319 since 1.18 (0 to 255 before)
Size: 512 x 512 blocks, 32 x 32 chunks

Neighbouring region files (north is up, west is left)

Numbers along the top and left edges are block coordinates at each region boundary. The amber square is your chunk.

Deleting region files by hand? FadeHost prunes unvisited chunks from the panel.

See a heatmap of where players actually go, pick the chunks nobody has visited and remove them in one click, with a backup taken first. Region, entities and poi files are rewritten together and the terrain regenerates on the next visit. Minecraft hosting from $2.50/mo.

See FadeHost →

How region files work

Minecraft Java Edition saves the world in region files using the Anvil format. The maths is two divisions that always round down: a chunk is 16×16 blocks, so chunk = floor(block ÷ 16); a region is 32×32 chunks (512×512 blocks), so region = floor(chunk ÷ 32). The file is named r.<regionX>.<regionZ>.mca. Y never changes the file: a region holds every chunk in it from the bottom of the world to the build limit.

Worked example

Block 1000, 70, -2500 is in chunk 62, -157 (1000 ÷ 16 = 62.5 rounds down to 62, and -2500 ÷ 16 = -156.25 rounds down to -157). Chunk 62, -157 is in region 1, -5 (62 ÷ 32 rounds down to 1, and -157 ÷ 32 = -4.9 rounds down to -5), so the file is r.1.-5.mca. Inside that file the chunk sits at local position 30, 3, index 126 of 1,024, and the region covers blocks X 512 to 1023, Z -2560 to -2049.

The other way round: r.-2.5.mca holds chunks X -64 to -33, Z 160 to 191, which is blocks X -1024 to -513, Z 2560 to 3071.

Where region files live

The folder depends on the server software and the game version. All paths are relative to the server folder, and world is the level-name from server.properties.

Dimension	Vanilla, Forge, Fabric, NeoForge (before 26.1)	Paper, Spigot, Purpur (before 26.1)	Minecraft 26.1 and newer (any server)
Overworld	`world/region`	`world/region`	`world/dimensions/minecraft/overworld/region`
Nether	`world/DIM-1/region`	`world_nether/DIM-1/region`	`world/dimensions/minecraft/the_nether/region`
End	`world/DIM1/region`	`world_the_end/DIM1/region`	`world/dimensions/minecraft/the_end/region`

Next to every region/ folder sit entities/ (1.17 and newer) and poi/ (1.14 and newer) with files of the same name for the same area. Not sure which layout you have? A dimensions folder inside the world means 26.1 or newer; a world_nether folder next to the server jar means Paper, Spigot or Purpur before 26.1. A world upgraded from an older version can keep the old layout, so trust the folders you can see.

Reading a file name

Region coordinates count regions, not blocks. r.0.0.mca covers blocks 0 to 511 on both axes, r.1.0.mca covers X 512 to 1023, and negative coordinates start straight away at -1: r.-1.-1.mca covers X -512 to -1 and Z -512 to -1. Multiply the region coordinate by 512 for the first block and add 511 for the last.

Finding a chunk inside the file

A region file starts with an 8 KiB header: 1,024 four-byte location entries followed by 1,024 four-byte timestamps. A chunk with local position lx, lz (each 0 to 31) uses index lx + 32 × lz, so its location entry is at byte 4 × index and its timestamp at byte 4096 + 4 × index. The tool shows both, which is handy when you inspect a file with a hex editor or write your own parser.

Deleting a region file to regenerate terrain

Stop the server and take a backup. Deleting an .mca file permanently removes everything built in that 512×512 area.
Find the file above and open the folder for the right dimension and server layout.
Delete r.X.Z.mca from region/, and the files with the same name from entities/ and poi/.
Start the server. The area generates fresh the next time someone loads it, using the current seed and generator, so a changed datapack or a new version shows up there.

Need to reset a smaller area than a whole region? MCA Selector can delete single chunks from a map view without touching the rest of the file.

FAQ

What is a region (.mca) file?

Minecraft Java Edition saves the world in region files using the Anvil format. Each r.X.Z.mca file holds a 32×32 block of chunks, which is 512×512 blocks across X and Z at the full world height. The numbers in the name are region coordinates, not block coordinates.

Which region file holds coordinates X, Z?

Divide X and Z by 16 and round down to get the chunk, then divide the chunk X and Z by 32 and round down to get the region. The file is r.<regionX>.<regionZ>.mca. Block 1000, -2500 is in chunk 62, -157, which is in r.1.-5.mca. Dividing the block coordinate by 512 and rounding down gives the same answer in one step. The tool above does this and shows the folder for your server type.

Where are region files stored?

It depends on the server. Vanilla, Forge, Fabric and NeoForge before 26.1: world/region, world/DIM-1/region (Nether) and world/DIM1/region (End). Paper, Spigot and Purpur before 26.1: world/region, world_nether/DIM-1/region and world_the_end/DIM1/region. Minecraft 26.1 and newer on any server: world/dimensions/minecraft/overworld/region, world/dimensions/minecraft/the_nether/region and world/dimensions/minecraft/the_end/region. Replace world with the level-name from server.properties if you changed it.

How do I delete a region file to regenerate terrain?

Stop the server and take a backup. Find the file with this tool, then delete r.X.Z.mca from the region folder and the files with the same name from the entities and poi folders next to it. Start the server: the 512×512 area generates again the next time a player loads it, using the current seed and world generator. Everything built there is gone for good, so double-check the coordinates first. To reset a smaller area, delete single chunks with MCA Selector instead.

Why do negative regions look like r.-1.-1.mca?

Because coordinates are divided with rounding down (floor), not toward zero. Block -1 is in chunk -1, and chunk -1 is in region -1, so r.-1.-1.mca covers blocks -512 to -1 on both axes while r.0.0.mca covers 0 to 511. There is no region -0: the boundaries sit at multiples of 512 and the negative side starts right at -1.

How big is a region?

32×32 chunks, which is 1,024 chunks or 512×512 blocks across X and Z, from the bottom of the world to the build limit. On disk a file is usually a few MB and can reach a few tens of MB, depending on how many of its chunks have been generated and how detailed they are.

Does the Y coordinate matter?

Not for finding the file. A region file stores the full height of every chunk in it, so only X and Z decide which file you need. Y only picks the 16-block section inside the chunk, which matters when you edit chunks with an NBT tool.

What are the entities and poi folders?

They use the same region grid as region/ but hold different data. Since 1.17, mobs, items and other entities are stored in entities/r.X.Z.mca, and since 1.14 villager workstations, beds, portals and other points of interest are stored in poi/r.X.Z.mca. When you delete, copy or restore a region file, do the same with its entities and poi files so they stay in sync. Vanilla sometimes writes empty 0-byte files there, which is normal.

Where is the Nether on a Paper or Spigot server?

Before 26.1, Bukkit-based servers give every dimension its own world folder next to the server jar: world_nether/DIM-1/region for the Nether and world_the_end/DIM1/region for the End. The names follow the level-name, so a level-name of smp gives smp_nether and smp_the_end. Since 26.1, Paper uses the same layout as vanilla: world/dimensions/minecraft/the_nether/region.

Why is there no world/region folder in my Minecraft 26.1 world?

Minecraft Java 26.1 moved every dimension into world/dimensions/minecraft/. The Overworld region files are now in world/dimensions/minecraft/overworld/region, and the entities and poi folders moved with them. A world upgraded from an older version may still show the old layout, so use whichever of the two folders exists on your server.

How do I open or edit an .mca file?

Region files are binary NBT, so a text editor shows garbage. Use MCA Selector to view, select and delete chunks on a map, NBTExplorer to edit chunk data by hand, or Amulet to edit the world visually. Always work on a copy or on a stopped server.

How do I fix a corrupted region or chunk?

Back up the world, then use MCA Selector or Minecraft Region Fixer to find and delete the broken chunks; the game regenerates them on the next load. If a large area is damaged, delete the whole r.X.Z.mca file plus its entities and poi files. Restoring the file from a backup keeps the builds if you have one.

What is the difference between .mcr and .mca?

.mcr is the old McRegion format used before Minecraft 1.2 and .mca is the Anvil format used since. Both use the same r.X.Z naming and the same 32×32 chunk grid, so the tool works for either.

Does Bedrock Edition use region files?

No. Bedrock stores the world in a LevelDB database inside the db folder, with no per-region files. This tool is for Java Edition worlds, including Java servers that Bedrock players join through Geyser.