Minecraft Circle Generator

The blueprint is a grid seen from above: cells that are filled mark where to place a block, and empty cells mark where to leave a gap. When building the shape in the game, start with the widest row in the grid and lay it down first as a baseline on the ground, then add rows outward one at a time. This makes it much easier to notice a mistake before it spreads to the rest of the shape.

A circle is symmetric across both axes, so you only need to count one quarter of the grid and mirror it for the other three. On larger circles a single misplaced block is harder to spot, so it helps to mark a reference block every ten cells before you start placing anything.

It also helps to finish the outer outline before filling in the interior. When filled is the target style, placing the thin outline first and then filling inward makes it easy to catch a misaligned outline early, before the interior blocks are stacked on top of it.

Filled places a block in every cell that falls inside the circle. It works well for a solid floor pattern or the base of a tower, anywhere a full plane is needed rather than an outline.

Thin keeps only the cells on the edge of that filled area, specifically the ones missing at least one neighbor to the north, south, east, or west, which produces an outline about one block wide. Thick uses the same idea but also checks the four diagonal neighbors, so the resulting outline is a little wider and hides small steps in the curve. Thick tends to suit window frames or fountain rims where the shape is seen up close, while thin is often enough for decoration viewed from a distance.

• Does an even or odd diameter change the look? Both use the same formula, but an odd diameter leaves a single center cell while an even diameter meets at a seam of four cells in the middle.
• Why do larger circles look smoother? The size of a single block never changes, but as the grid grows, the same stair-step edge becomes a smaller fraction of the whole shape, so it reads as rounder.
• What does a total like 19 stacks plus 34 mean? A regular item stacks to 64 in the game, so the count is divided by 64: the quotient is the number of full stacks and the remainder is the extra blocks, which makes it easier to plan a shopping list before building.
• How noticeable is the difference between thin and thick? On a small diameter, a single extra block of width changes the look a lot, but on a large diameter that same extra width is a smaller fraction of the whole outline, so the difference becomes harder to notice.