Minecraft pixel circle generator
Circles are the thing Minecraft builders get wrong most often, because a circle on a square grid is a judgement call. This makes the judgement for you and gives you the block count before you start mining.
Building from the grid
Read it as a top-down blueprint: every filled square is one block. Build one full ring at ground level, then stack it for a tower, or step the diameter down layer by layer for a dome. The block count tells you what to bring — running out halfway up a tower is the classic way to lose an evening.
Odd and even diameters behave differently and it matters. Odd diameters have a true centre block, which is what you want if something goes in the middle — a beacon, a pillar, a nether portal. Even diameters have a 2×2 centre and produce a more symmetric-looking ring, which is usually what you want for pure decoration.
Diameters under about 7 blocks stop looking like circles at all, no matter how the math rounds — there simply aren't enough blocks to suggest a curve. If you need a small round shape, going up to 9 or 11 blocks reads far better than fighting a 5.
Questions
Should I use an odd or even diameter?
Odd if anything belongs in the exact centre — beacons, pillars, portals — because odd diameters have a single centre block. Even if it's purely decorative; those rings tend to look more symmetric.
How do I turn this into a sphere or dome?
Build a stack of circles with shrinking diameters. For a dome of radius r, the circle at height h has diameter 2 × √(r² − h²), rounded — generate each layer here and stack them from widest to narrowest.
Can I use this outside Minecraft?
Yes — it's a generic pixel-grid circle, so it works for any voxel or pixel-art context: Terraria builds, cross-stitch patterns, sprite work, or Rust base layouts. The text export is a plain # and . grid.