Minecraft Spawn Chunk Calculator

Spawn chunks are the area around a Java Edition world’s spawn point that stays loaded even when nobody is nearby, which made them the classic place for iron farms, item sorters and redstone clocks. This calculator shows exactly which chunks and block coordinates are kept running for your version and game-rule setting.

How to use this tool

1. Choose your Java Edition version.
2. Enter the world spawn X and Z (a compass points to it; /setworldspawn changes it).
3. For 1.20.5 – 1.21.8, enter the spawnChunkRadius game rule (2 unless someone changed it).
4. Check the entity-processing range and your version’s activity requirements before placing a farm.

Formula

Entity-processing side = 2r − 1 chunks · lazy side = 2r + 1 · loaded side = 2r + 3

r is the spawn chunk radius (fixed at 10 in 1.14–1.20.4, configurable in 1.20.5–1.21.8; zero disables loading). The spawn ticket gives the spawn chunk load level 32 − r, and the level rises by 1 per chunk outward. Levels of 31 or less are entity ticking, 32 is block ticking (lazy) and 33 is border.

Example

In 1.20.4 with world spawn at X 100, Z −250, the spawn chunk is 6, −16. With r = 10 the entity-processing area is 19 × 19 = 361 chunks, covering X −48 to 255 and Z −400 to −97. In 1.21 with the default radius of 2, the same idea gives only 3 × 3 entity-processing chunks.