What your result means
Blocks needed is the total for the whole shape, not per layer. Stacks of 64 is the same number in inventory terms — the figure that tells you whether this is a one-trip job or a mining expedition. Shulker boxes assumes 27 slots of 64, so 1,728 blocks per box, which is how you plan transport for anything large. Layers to place is how many horizontal passes the build takes, useful for pacing a session.
Hollow shapes are cheap; solid ones are not
A 20 × 20 room five blocks high needs 1,180 blocks. The same footprint filled solid needs 2,000 — and a 20-block cube needs 8,000, over four shulker boxes.
That is the cube law at work: doubling a dimension doubles a wall but multiplies a solid by eight. It is why big builds are almost always shells, and why it pays to check the count before you commit to a material you have to mine or trade for.
How it works
Each shape reduces to simple multiplication. A floor is length × width. A wall is length × height. Four walls are the perimeter of the footprint — 2L + 2W − 4, subtracting the four corners that would otherwise be counted twice — multiplied by the height. A room adds a floor and a roof to that. A solid cuboid is length × width × height. The totals are then divided by 64 for stacks, 1,728 for shulker boxes and 3,456 for double chests.
How to use this calculator
- Pick the shape that matches what you are building.
- Enter the footprint dimensions in blocks. A single wall only needs length and height; a flat floor only needs length and width.
- Read the block total, then the stacks figure — that is what you need to carry.
- For anything over a few thousand blocks, check the shulker-box row before setting out.
- Building something round instead? Use the Minecraft circle generator for the footprint, then multiply its block count by your height.
Formula
L and W are the footprint length and width in blocks, H is the height. The −4 in the perimeter removes the double-counted corner blocks. A room adds two full floors (2LW) for the floor and roof. Stacks are the total divided by 64; a shulker box holds 27 stacks (1,728) and a double chest 54 stacks (3,456).
Example calculation
A 20 × 20 room, five blocks high, with a floor and a roof:
Walls: 76 × 5 = 380 blocks
Floor + roof: 2 × (20 × 20) = 800 blocks
Total = 1,180 blocks
That is 18 stacks + 28, or about 0.68 of a shulker box
Drop the floor and roof and the same walls cost 380 blocks — under six stacks. Most of a room’s material goes into the surfaces you walk on, not the walls.
Frequently asked questions
Does this include windows, doors or decoration?＋
No — it counts a complete shell. Subtract roughly one block per window pane and two per doorway, or just gather 5–10% extra, which is what most builders do anyway.
How many blocks fit in a shulker box?＋
27 slots of 64, so 1,728 blocks of any fully stackable material. A double chest holds 54 slots, or 3,456 blocks. Items that stack to 16 or 1 — buckets, beds, shulker boxes themselves — hold far less.
What about round buildings?＋
Use the circle generator to get the block count for one circular layer, then multiply by your wall height. For a cylinder five blocks high with a 25-block outline (68 blocks per layer) that is 340 blocks.
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Assumptions & limitations
Every figure here comes from a simplified model. Keep these limits in mind when reading your result:
- Shapes are complete shells with no openings; windows, doors and decorative cut-outs are not deducted.
- Every position is filled with one full block. Slabs, stairs and fences are not modelled, and they change both the look and the count.
- Stack, shulker and chest figures assume a fully stackable material at 64 per slot.
- Scaffolding, supports, lighting and any blocks lost to mistakes are not included — gathering 5–10% extra is sensible.
- Terrain is treated as flat. Building into a slope needs more material for foundations.