Minecraft Chunk Coordinate Calculator
Convert Minecraft block coordinates to chunk and region coordinates and back, with local position, section Y and the .mca region header offset.
Minecraft uses three coordinate grids: blocks, 16 × 16 chunks, and region files that each hold 32 × 32 chunks. Map editors, world-pruning tools, server commands and seed-finding guides often give a location in chunk or region terms rather than blocks. This converter goes from block coordinates to chunk and region, and back from a chunk or a region file name to the blocks it covers.
How to use this tool
- Choose whether you are starting from block coordinates, chunk coordinates or a region file name.
- Enter the X and Z values (for a region file, the two numbers in r.X.Z.mca).
- In block mode, optionally add Y to get the section and full local position.
- Read the matching chunk, block range and region details.
Formula
Chunk = ⌊block ÷ 16⌋, Region = ⌊chunk ÷ 32⌋ = ⌊block ÷ 512⌋
⌊ ⌋ rounds down, so negative values move away from zero. Position inside the chunk = block mod 16 (always 0–15). Inside a region a chunk sits at (chunk X mod 32, chunk Z mod 32), and its 4-byte location entry starts at byte 4 × (local X + local Z × 32) of the file header.
Example
Block X 1234, Y 64, Z −567 is in chunk 77, −36 (1234 ÷ 16 = 77.1 and −567 ÷ 16 = −35.4, both rounded down) and section Y 4. Chunk 77 ÷ 32 = 2.4 and −36 ÷ 32 = −1.1 give region file r.2.-2.mca. Inside that file the chunk is at local position 13, 28, so its header entry starts at byte 4 × (13 + 28 × 32) = 3,636.
Frequently asked questions
How do I find chunk coordinates in Minecraft?
In Java Edition the F3 screen shows a Chunk line with your position inside the chunk and the chunk coordinates. In Bedrock, take your block X and Z and divide by 16, rounding down, or enter them here.
Which region file contains my base?
Divide your block X and Z by 512 and round down. A base at X 1234, Z −567 is in r.2.-2.mca, inside the world folder's region directory.
Why are negative chunk numbers off by one?
Because the maths rounds down rather than toward zero. Blocks −16 to −1 make up chunk −1, while chunk 0 starts at block 0.
Does this work for the Nether and the End?
Yes. Every dimension uses the same 16-block chunks and 32-chunk regions; only the folder that holds the region files differs.
Sources
Last updated: 2026-10-30