Pixel Circle Generator

Circles for cross-stitch, knitting, and grid crafts

Every craft that lives on a grid hits the same wall: fabric, charts, and beads only come in squares, and a circle drawn on squares has to be approximated. Do it by eye and you get lumps — one row juts out, the curve flattens where it shouldn't. The chart above is the mathematically even version: each cell is filled exactly when its center falls inside the true circle, which distributes the "steps" as symmetrically as the grid allows. For cross-stitch, read the hover counter as your stitch count — point at any cell and you get the run length of that row and column, which is exactly the "stitch 7, step up, stitch 3" information you'd otherwise count off a printed chart with a pencil. Knitters charting colorwork can read rows the same way; each grid row is a chart row.

Perler / fuse bead boards

Standard square pegboards are 29×29 pegs, and large ones interlock into bigger fields — so the width/height inputs map one-to-one onto pegs. A 29-cell circle fills a single board edge-to-edge; anything larger, plan on linked boards and use the PNG export as your placement reference (zoom it on a phone propped next to the board — the grid lines survive scaling because the export draws them in). Odd diameters have a single center peg, which makes centering on a board with a marked middle much easier; that's the even/odd note below.

Even vs odd sizes — why it matters

An odd-width circle (31, 45…) has a true center cell, so the shape is symmetric around a single column and row — easiest to center and count from. An even width (30, 44…) has its center on a grid line, so the middle is a 2×2 cluster and the top/bottom/side runs come in pairs. Neither is wrong; they're different symmetries. If your pattern needs a single centered motif (an eye, a French knot, a highlight bead), choose odd. If you're tiling or mirroring halves, even often lays out cleaner. Toggle one cell of width and watch the top row change — that's the whole effect.

Ovals and ellipses

Untick Perfect circle and width and height set independently, which turns the generator into an ellipse charter — the shape crafts actually need more often than a true circle (eggs, eyes, petals, hoop-shaped borders). The same center-sampling rule applies on both axes, so an oval keeps left/right and top/bottom symmetry exactly. Wide, shallow ovals (say 45×13) develop long flat runs at top and bottom; that's geometry, not an error — the true ellipse really is that flat there, and the hover counts give you those run lengths precisely.

The algorithm, honestly

Classic drawing literature solves this with the midpoint circle algorithm — an integer-only method from the era when multiplication was expensive, which walks one octant deciding "step sideways or step diagonally" and mirrors the result eight ways. The center-sampling rule this page uses (fill a cell if its center is inside the ellipse) produces the same cell set for circles while extending cleanly to ellipses and to filled shapes, and the outline is then the filled set minus its interior — which is also how thickness works: a thickness of 3 keeps every cell within three erosion steps of the edge. The result is always a connected, symmetric, minimal-lump ring.

Frequently asked questions