5 mm graph paper, US Letter
Five-millimetre squares on an 8.5 × 11 inch sheet — the metric ruling on the imperial page, which is what a great deal of American science work actually needs.
Opens with these settings already loaded. Change anything you like, then download as PDF, PNG or SVG.
Why an American would want millimetre squares
US school paper is imperial but US science teaching is not. Lab measurements come in centimetres and grams, textbook problems are worked in SI units, and a graph plotted on quarter-inch squares forces a unit conversion at every tick mark. Five-millimetre squares with centimetre majors let you read the axis straight off the metric ruler already sitting on the bench, which removes an entire class of arithmetic slips from a lab write-up.
The edges will not divide evenly
A 5 mm grid does not fit a whole number of times into 8.5 inches, so something has to give. This generator centres the field and leaves an even margin on both sides, rather than starting flush at the left and stranding a half column at the right edge. If you need the grid to reach a particular edge instead — for a page that will be trimmed, or joined to another sheet — reduce the margin and let it run out to the trim line.
Centimetre majors are worth switching on
Set major lines every 5 squares and the sheet gains the 5 mm and 10 mm hierarchy of a printed graph pad. On a page this size that is roughly 40 by 52 small squares — far too many to count reliably one at a time, and few enough that counting in centimetres is quick. The heavier lines cost almost nothing in toner, since only every fifth line is drawn dark.
Printing it accurately
This only measures correctly if your printer doesn't rescale the page. In the print dialog set Scale: 100% — not "Fit to page" or "Shrink oversized pages". If you're not sure it worked, print the calibration page, measure the ruler on it with a real ruler, and it will tell you exactly what your printer is doing to the page.