How to use it
- Enter the number of items, for example the block count from a generator.
- Choose the stack size: 64, 16 or 1.
- Read the stacks and the extra items, and how many chests or shulker boxes you need.
- To go the other way, enter full stacks and extra items in the second box.
How the calculation works
The tool divides the number of items by the stack size. The whole part is the number of full stacks and the remainder is what is left. A partly filled stack still takes a whole slot, so the slot count is the number of full stacks plus one if there is a remainder. The chest counts are the slot count divided by 27 (single chest or shulker box) or 54 (double chest), rounded up.
For 1,000 blocks at 64 per stack that is 15 full stacks and 40 left over. The 40 sit in their own slot, so 16 slots in total. One single chest has room for them.
Quick reference
| Container | Slots | Items at 64 per stack | Items at 16 per stack |
|---|---|---|---|
| Single chest | 27 | 1,728 | 432 |
| Double chest | 54 | 3,456 | 864 |
| Shulker box | 27 | 1,728 | 432 |
A worked example: a big build
A hollow sphere with a diameter of 51 needs 6,642 blocks. That is 103 stacks and 50 extra blocks, so 104 slots. Four double chests hold 216 slots, and that is more than enough, but a single stack of one block type is only the start. A real build uses several block types, so you divide the total by the share of each type. If the sphere uses 5,000 blocks of one type and 1,642 of another, you need 79 slots for the first and 26 for the second. Together they are 105 slots, or 4 shulker boxes.
The same logic applies to pixel art: the materials list shows each block with its stacks, so you can sort the chests by block.
Tips for moving big builds
- Use shulker boxes for travel. They keep their contents when you break them, so you carry 27 slots in one inventory slot.
- Sort by block type. One chest per block type makes it much easier to refill while you build.
- Round up. Plan for a few extra stacks. A single misplaced block or a changed design will cost more than the spare blocks.
- Check the stack size. If you build with items that stack to 16, such as signs or buckets of some kinds, switch the stack size in the tool.
Common mistakes
- Forgetting the leftover slot. 65 items are 2 slots, not 1.
- Mixing block types in one number. The slots are per kind of item.
- Thinking a shulker box fits inside a shulker box. It does not.
- Assuming every item stacks to 64. Some stack to 16 and some do not stack.
Related generators
The block counts to feed in come from the generators. Try the circle generator for walls and floors, the sphere generator for balls and bubbles, or the pixel art generator, which also lists how many blocks of each kind you need.
Sources and notes
Chest and shulker box sizes: Minecraft Wiki, Chest (27 and 54 slots) and Shulker Box (27 slots, cannot be nested), checked on 25 October 2026. Stack sizes: Stack. BlockShapes is not affiliated with Mojang or Microsoft.
Frequently asked questions
How many items are in a stack in Minecraft?
Most blocks and items stack to 64. Some items, such as ender pearls and snowballs, stack to 16. Tools, armor and other items with durability do not stack, so every one takes a slot. The Minecraft Wiki lists the details for each item.
How many slots does a chest have?
A single chest has 27 slots and a double chest has 54. A shulker box also has 27 slots.
How many blocks fit in a shulker box?
A shulker box holds 27 slots, which is 1,728 blocks of a type that stacks to 64. Shulker boxes cannot be placed inside each other.
How many stacks is 1,000 blocks?
1,000 blocks are 15 stacks and 40 extra blocks. That takes 16 slots, so one chest holds it with room to spare.
How do I turn stacks back into blocks?
Multiply the stacks by 64 and add the extra blocks. Three stacks and 8 blocks are 200. The second part of the tool does this for you.
Does this work for mixed items?
Each kind of item needs its own slots, so calculate each kind separately and add the slot counts. A stack of 64 cobblestone and a stack of 64 oak planks need two slots.