Minecraft Build Material Calculator
Editions: Java + Bedrock (identical) · Verified: Java 26.3 / Bedrock 26.50 · 2026-09-16 · Updated 2026-09-16
Type a footprint and this counts the blocks — walls, floor, solid, or full hollow shell — subtracts your doors and windows, and converts the answer into stacks, shulker boxes, logs to chop, or blocks to smelt.
The worked example
An 11×9 cottage, walls five high: the footprint ring is 11×9 minus the 9×7 interior — 36 blocks per layer — times 5 is 180. One door (2 blocks) and four 2×2 windows (16) cut it to 162 blocks: 2 stacks and 34 loose, 3 inventory slots, one trip. In planks that is 41 logs (4 planks each); as a slab texture it is 81 full blocks (3 craft into 6); as stairs, 243 (6 craft into 4); as smooth stone, 162 smelts at one for one. The full hollow shell — same footprint with floor and ceiling — is 306 blocks before openings.
Conversions this tool uses
| Recipe | In | Out | Blocks per unit |
|---|---|---|---|
| Planks | 1 log | 4 planks | 0.25 |
| Slabs | 3 blocks | 6 slabs | 0.5 |
| Stairs | 6 blocks | 4 stairs | 1.5 |
| Smelting | 1 raw | 1 smelted | 1 |
Recipe yields verified against the Minecraft Wiki's crafting documentation; sources in the material math guide.
Questions builders actually ask
How many blocks do four walls take?
Footprint area minus the interior, times the height: for an L by W footprint that is L times W minus (L-2) times (W-2), per layer of height. An 11 by 9 cottage five high is 36 blocks per layer, 180 total, before cutting openings.
How does the calculator handle doors and windows?
Doors subtract a 1 by 2 hole each and windows subtract width times height each, straight off the wall total. The cut is clamped so the result never goes below zero, and openings only apply to wall and hollow-box shapes.
How many logs, slabs, or stairs is that?
One log crafts into 4 planks; 3 blocks craft into 6 slabs, so a slab surface needs half as many full blocks; and 6 blocks craft into 4 stairs, so stairs cost one and a half blocks each. Smelted blocks like stone convert one to one from their raw form.
Does a 1-block-thick wall count corners twice?
No. The formula counts the footprint ring exactly once — the four corners are shared between walls, which is why two walls of 11 and two of 9 come to 36 per layer rather than 40.