A section with only solid stone will have one palette entry while a section with a redstone contraption or a market square by your favourite builder can have hundreds of entries. The palette itself can vary wildly in size depending on how many different kinds of blocks there are and how complex are they. Name: 'minecraft:light_blue_stained_glass_pane', east: 'true', south: 'true', waterlogged: 'true'ДЄnd then stores an array of indices in the palette, e.g. To store each block in a section the game gets collects all unique blocks+states in a 'block palette' e.g. This means that the the region file contains 1024 chunks * 5 sections = ~5000 sections.Д®ach section contains 16 x * 16 z * 16 y blocks = 4096 blocks. (because they are small number compared to the number of blocks) we are ignoring entities like mobs, dropped items, arrows, etc.

(they are relatively small percentage of the terrain)

we are ignoring tile entities like chests, furnaces, signs etc.

the average section height of each chunk is 5 (ocean level is y=64, so this sounds about right).

the region is fully explored (contains all 1024 chunks).

Now we are going to make some assumptions. For example if the terrain goes up to y=82, the game will store the bottom 6 sections (6*16=96 height, just enough for height 82) and all blocks above y=96 are implicitly considered to be air and are not stored in the file. The game stores information only about the bottom sections where there are blocks. We can however make some estimations for the average size of a fully explored region.Д®ach chunk is split vertically in 16 sections each 16 blocks high (stacked on top of each other). Since each region is generally explored to a different extent, the sizes of region files can vary wildly and an average number is not very useful. The region file may contain less than 1024 chunks if the region is not fully explored and some chunks are not yet generated. All chunk in a single file are from what is called a 'region' of 512x512 potential blocks. The actual terrain is stored in the region, DIM1 and DIM-1 sub-folders of the world save folder.Д®ach file there contains up to 1024 (32x32) chunks (you can check out What is a chunk). This answer is updated for 1.13 block format change, see the answer history for older versions of the world storage format

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