A world is 30,000,000 blocks deep in each cardinal direction.
So that makes a square of 60,000,000 x 60,000,000 blocks.
With Minecraft 1.2 comes the new Anvil format including 256 block height. The Anvil format has 12Bit per block. So 1.5byte per block. A chunk (16x16x256 blocks) has then the size of 98.3kb.
We now calculate the square down to the chunks. 60.000.000 / 16 = 3.750.000 chunks per page.
Now multiply the whole with the size of the single chunk. 3.750.000 x 3.750.000 x 98,3kb = 1.382.343.750.000.000kB
This in turn is 1,287,407 terabytes or 1,257 petabytes.
The maximum size of a world is therefore around 1.3 exabytes.
However, this size will probably never be reached, at most with a few thousand bots flying around the world around the clock. Even then, you would first need a server that can store this huge amount of data. For this amount of data you would need about 107.284 12TB hard disks like this one. With a price of approx. 300€ (Let’s assume a corresponding bulk purchase) we would come to over 32.185.175 Euro only for the hard disks, the costs for the servers not even included.
- A Minecraft world has a maximum renderable area of 60,000×60,000 km or 3.6 billion km². This is seven times the roughly spherical surface of the Earth, which is about 510 million km².
- In total, there can be up to 1.382 trillion (1.382×1018) blocks in a Minecraft world with a build height of 384 blocks. As a written out number: 1.382.000.000.000.000