Start with the outside dimensions
Enter the number of blocks across the outside edge. Circle mode mirrors the width into the height; Oval mode keeps both values independent. Dimensions are clamped to the supported 3–256 block range.
Choose the boundary
Use Outline for a ring and Filled for a complete footprint. Thickness adds inward layers to an outline without changing the outside dimensions. Odd center keeps odd dimensions when a single center block is important.
Use the workbench
Keep the grid and center guides visible while marking the top, bottom, left, and right extremes. Click planned blocks as you place them. Use the row plan when a straight run is easier to count than a visual curve.
Save or export the plan
Copy the versioned share URL to reproduce the same settings later. PNG is useful for a quick reference; CSV, TXT, and Markdown are text-friendly plans; Litematic is intended for compatible Java mod workflows.