Free Custom Grid Maker

Consider a printed worksheet. You want 10 mm cells because that is what a ruler reads easily and what a child's hand can work within. Specifying by count means computing 210 ÷ 10 and 297 ÷ 10, deciding what to do with the remainder, and repeating the whole exercise if the paper size changes.

Specifying by size means typing 10. The grid works out that A4 takes 21 cells across and 29 down — 609 whole cells — and puts the remainder where it belongs.

The same logic covers a long list of practical cases. A 5 mm grid gives 42 × 59 on A4, which is the standard fine graph paper. A quarter-inch grid is the classic American equivalent. A 20 mm grid gives 10 × 14 and is coarse enough for a young child. A 25 mm grid gives 8 × 11 and is what a lot of transfer work uses because an inch is easy to eyeball on the receiving surface.

Craft work is where this matters most, because the receiving surface has a grid of its own that you do not control. Cross-stitch fabric is specified in threads per inch — 14-count aida has 14 stitches to the inch, so a grid at one-fourteenth of an inch corresponds to the fabric exactly.

Knitting is the same problem with different numbers. A gauge swatch gives stitches and rows per ten centimetres, and a chart drawn on a grid matching that gauge produces a garment the size you intended. A chart drawn on square cells when the gauge is not square produces one that is not.

That last point is worth dwelling on, because knitting gauge is almost never square. Rows per centimetre and stitches per centimetre differ, typically with more rows than stitches, so a design charted on square cells comes out compressed vertically in the finished fabric. The fix is a grid whose cells match the gauge ratio.

The unit choice matters more than it looks. Working in the unit your instruments read is the single largest error reduction available in any transfer process, and it is free. Mixed units — a design in inches marked out with a metric rule — is the classic source of the error that is discovered after the cut.

Pixels are the fourth unit and they serve a different purpose: matching a digital canvas exactly. For pixel art, sprite work, icon grids and anything that will be displayed at 1:1, a grid specified in pixels is the only one that lands on pixel boundaries.

The margin control exists for the printed case. Every worksheet, every plan and every drawing sheet has a border, and the border is not decoration — it is where the sheet is held, where it is punched, and where things get written that are about the drawing rather than in it.

A grid running to the edge of the paper is also a grid that will be clipped by any printer with a non-printable margin, which is nearly all of them. Insetting by 5% avoids losing the outer row and column to the hardware.

The labelling serves collaboration. A grid with no labels is usable by one person; a grid with labels is usable by two, because they can name a cell rather than point at one. That distinction turns out to be the whole difference between a personal tool and a teaching one.

The two label modes serve different situations. A1-style — letters across, numbers down — is what people navigate by eye, and it is self-describing so C4 cannot be confused with 4C. Numeric pairs, 1-1 and 2-2, suit anything that will be read aloud, dictated, or entered into a spreadsheet or a stitch chart.

Label size runs from 40% to 220% for the same reason. A worksheet held at reading distance wants small labels that do not compete with the drawing; a demonstration on a wall wants labels legible across a room. One setting cannot serve both.

The half-grid subdivision doubles the resolution at 45% opacity without renumbering. That combination is what makes it useful: the coarse coordinates survive, so a note that says "C4" still points at the same place, and the finer level is visibly subordinate rather than competing.

The highlight singles out one cell at 2.2 times the line weight, and it is more useful than it sounds. Over a transfer that takes hours, losing your place is the most common interruption, and a marked cell is a bookmark. In a lesson it is a pointer that survives the teacher walking away from the screen.

There is one thing to be careful about when working by size: the cell size is applied to the canvas as drawn, so if you subsequently change the paper format the count changes rather than the size. That is the correct behaviour — you asked for 10 mm cells — but it means a grid set up for A4 will have a different number of cells on A3.

Which is usually what you want and occasionally is not. If the requirement is the same grid at two sizes, specify by count; if it is the same cell size on two sheets, specify by size. The mode switch exists precisely because both requirements are real.

The grid draws over your own image rather than exporting a fixed template because the size question is usually asked against something. Whether 10 mm cells are fine enough for a particular subject is a judgement about that subject, made by looking.

The export sizes itself from the paper format and the DPI you choose rather than from your screen, which is what makes a specified cell size meaningful — a 10 mm cell here prints as a 10 mm cell there. SVG keeps every line editable and every label as text. The custom grid overlay page works through them, beside the rest of the basic drawing grids.

Everything runs in your browser. Images you load are never uploaded, because there is no server for them to reach. The drawing, the transform and the export all happen on your own machine.