Minecraft octagon generator 8 sides, exact
Pick a width and get the octagon in blocks with the count and a 3D view. A 21 wide octagon outline takes 56 blocks, 357 filled. Add layers for an octagon tower, or export it.
Pick a size, then press Start!
Expert mode is on. All the controls, exact numbers and file types.
1 layer
Building 3D view… the 2D plan already works.
3D needs WebGL, which this browser has turned off. The 2D layer view has everything you need.
Drag to spin it around
How big?blocks across
Wall
How tall?
Extras
Blockfor the walls
56
blocks in all
56
less than 1 stack · Fits in 1 chest · About 5–10 minutes
Row by row (text version of this layer)
Octagon sizes at a glance
Outline and filled counts for common widths.
How to use it
4 steps
- Set the width (box size, flat side to flat side). Odd widths have a single centre block.
- Pick the wall: thin, thick or filled.
- Add layers for a tower and pick a block.
- Build or export with build mode, the A4 sheet or a schematic file.
Questions builders ask
How many blocks is a 21 wide octagon?
A 21 wide octagon outline is 56 blocks thin and 80 thick; filled it is 357 blocks. The 21 is the width from one flat side to the opposite side.
Octagon or circle: which is easier to build?
The octagon: its eight sides are four straight runs (north, south, east and west) and four 45° diagonals that step one block at a time, so it is quick to count. A circle of the same width has more, uneven steps but looks rounder from a distance.
How do I make an octagon tower?
Set the layers and a thick wall. A 15 wide octagon tower, 8 layers high, is 448 blocks.
Are the eight sides the same length?
In the true shape they are. On the block grid a diagonal side becomes a staircase, so it shows fewer blocks than a straight side of the same length. The generator places a block when its centre is inside the regular octagon, the same rule as the circle generator.