How is the Minecraft world size on disk worked out?

Minecraft

World Size on Disk

How much disk a Minecraft world takes is set almost entirely by the world border, because the border limits how much terrain can ever exist. Next to the square of the radius, everything else barely registers.

World Size on Disk

Assumes the world is generated all the way to the border. A partly explored world will be smaller.

World border radius (blocks)

Version

Include the Nether

Include the End

32.2 GB

Disk needed

0.40 million chunks

31.7 GB

Overworld

0.5 GB

Nether

Built at one eighth scale — a sixty-fourth of the area

Region files reserve space in 4 KB sectors, so a thinly explored world uses more disk than its chunk count implies.

How the numbers are worked out

The border is a square, so the area inside it is the radius doubled and then squared, split into sixteen-block chunks. A saved chunk takes roughly 45 KB up to 1.17 and roughly 85 KB from 1.18 on — that update made the world fifty per cent taller, and saved chunks grew to match. The Nether is built at one eighth scale, so the same border covers an eighth of the distance each way and a sixty-fourth of the area, which is why it adds much less than most people assume.

The formula

chunks = (2 × border radius ÷ 16)²
nether chunks = (2 × radius ÷ 8 ÷ 16)² · end ≈ 2% of overworld
disk = chunks × KB per chunk (45 KB pre-1.18, 85 KB from 1.18)

Common mistakes

This treats the world as generated all the way to the border — the worst case, and the right figure to plan for if you pregenerate. A world players have only roamed through will be far smaller. In the other direction, region files reserve space in 4 KB sectors, so a sparsely explored world uses more space than its chunk count implies; the pregenerated estimate and the patchy reality close in on each other from opposite sides.

How much RAM a Minecraft server needs Check a Minecraft server’s status Minecraft server hosting All calculators