Green cells are blocks to place. Dashed lines mark the center. Hover a cell to read its row and column.
Type the diameter you want (or a separate width and height for an oval), choose thin, thick or filled, and read the chart: every green cell is one block. The dashed guides mark the exact center, so you can anchor the shape to a build point in your world, and the block counter tells you how much material to bring. For big builds, download the PNG chart and keep it open while you place blocks.
Minecraft has no round blocks, so a "circle" is really the set of blocks whose centers fall closest to a true ellipse — the same pixel-circle math used in classic block charts. Odd diameters give you a single center block, even diameters sit between two blocks; both work. Sphere mode slices a ball into horizontal layers and gives you one chart per layer, which is how domes, planets and storage spheres are actually built in survival.
Set the width and height, pick an outline style, then copy the highlighted pattern row by row in game. The generator shows a block grid with center guides, the exact block count, and a downloadable PNG chart you can keep on a second screen while you build.
Yes — switch the mode to Sphere and it slices the sphere into horizontal layers. Build each layer from its chart, bottom to top, and you end up with a full hollow sphere.
A thin outline marks the minimum blocks needed, so diagonal steps touch only at corners. A thick outline adds a block at each corner step, which looks smoother and gives you a ring you can walk on.
An odd diameter has a single center block and column; an even diameter is centered between two blocks. Both are valid — the grid's center guides show exactly where the middle falls so you can line the shape up in your world.