Generate printable grid and graph paper at any square size, on A4, A5, B5 or Letter. The squares come out the size you asked for.

Print at 100%, or none of this works

This is the one thing that ruins printable graph paper, and it is not the generator’s fault: “fit to page” rescales the sheet. Your print dialog almost certainly has it switched on by default, usually called Fit, Shrink to fit or Scale to fit, and it will helpfully shrink an A4 design onto A4 with a margin, making every 5 mm square about 4.7 mm.

Set scale to 100% — or Actual size — and turn margins off. The page already carries its own margin, and the sheet is generated at the exact size of the paper you picked.

Once printed, measure ten squares rather than one. Ten 5 mm squares should span exactly 50 mm; an error too small to see across one square is obvious across ten.

How the squares are sized

Everything here is calculated in millimetres and rendered in millimetres. Nothing is converted to pixels at any point, because a pixel has no fixed physical size — a generator that draws to a canvas has to assume a screen density, and that assumption is exactly where 5 mm becomes 4.8 mm.

Only whole squares are drawn. If 55.4 rows fit inside the margins, you get 55 rows and the leftover 2 mm is added to the margin rather than printed as a partial square. A strip of half-squares along one edge is not grid paper.

Choosing a size

5 mm is standard school graph paper, and the default here.
2 mm is fine engineering paper. It is close to the limit of what an inkjet prints cleanly and what most people can write on.
10 mm suits handwriting practice, planning and bullet journalling.
20 mm is for children learning to form letters and numbers.

Line colour matters more than it looks. A mid grey stays visible while you draw but disappears from a photocopy or a scan, which is usually what you want if the sheet is going to be reproduced. Black lines will compete with your own.

Paper sizes

A4, A5 and B5 use the exact ISO 216 dimensions rather than values derived by halving A0 — the standard rounds to whole millimetres at every step, and paper is cut to the rounded value. Letter is 8.5 × 11 inches converted at exactly 25.4 mm to the inch.

Writing Chinese?

Squared paper is not what Chinese composition is written on. That is 稿紙, which fixes the number of characters rather than the size of the squares, and it has its own page here — see manuscript paper.

Nothing is uploaded

The sheet is drawn by your own browser and printed by your own printer. There is no server in this at all.