How to print an actual size ruler
- Choose the ruler: inches, centimeters or both. The default sheet has an inch ruler, a cm ruler and a strip with inches on one edge and centimeters on the other.
- Press Print ruler and set the scale to 100% or Actual size. Never use Fit to page: it shrinks everything a little.
- Check the scale with any credit or debit card. It should fit the box on the sheet exactly, 85.6 × 54 mm.
- Cut along the dashed lines. Glue the strip to a piece of card if you want it stiffer.
Printable ruler inches and cm: what's on the sheet
| Ruler | On US Letter | On A4 | Marks |
|---|---|---|---|
| Inch ruler | 10 inches | 10 inches | 1/16, 1/8 or 1/4 inch |
| Centimeter ruler | 25 cm | 27 cm | Millimeters, with a longer 5 mm line |
| Combined strip | Inches on top, cm below | Same | Both scales on one strip |
The printable ruler in inches uses the classic tick lengths: whole inches longest, then halves, quarters, eighths and sixteenths. The printable ruler cm scale marks every millimeter, with a medium line at 5 mm, so it also works as a printable ruler mm scale that reads like a normal school ruler. Choose 1/4 inch marks for children who are just learning to measure.
Why the card check matters
Printers and PDF viewers often shrink a page slightly to fit their margins, which turns a 10 inch ruler into a 9.7 inch one without any warning. A standard bank card is the same size worldwide (ISO/IEC 7810 ID-1, 85.60 × 53.98 mm), so it's a reliable check. If the card is bigger than the box, print again at 100%. A US dollar bill, 6.14 inches long, works as a second check against the inch ruler.
A printed ruler is fine for ring and shoe sizes, crafts, sewing and quick checks. Paper stretches a little with humidity, so for precise work use a real metal ruler. Need a grid instead? Print graph paper at true size, or check your printer first with a printer test page.
How we tested this tool
We printed the ruler sheet to PDF with Microsoft Edge on Windows and measured the file: the page is US Letter landscape on one sheet, one drawing unit equals 1 mm, the inch marks are 25.4 mm apart and the centimeter marks 10 mm apart, and the card box is drawn at 85.6 × 53.98 mm. Testing also caught two problems we fixed before publishing: the Letter ruler first came out at 9 inches instead of 10, and a strip label overlapped the centimeter marks. We checked every option, the A4 version and the layout at a 375 px phone width. We haven't yet printed it on a range of real printers ourselves. If you print one, tell us how it came out.
Frequently asked questions
How do I make sure the printable ruler is actual size?
Print with the scale set to 100% or Actual size, not Fit to page. Then lay a credit or debit card on the box printed on the sheet: a standard card is 85.6 mm by 54 mm and should fit it exactly. If it doesn't, the printer scaled the page.
How long is the printable ruler?
On US Letter in landscape you get a 10 inch ruler and a 25 cm ruler. On A4 you get 10 inches and 27 cm. The rulers stop short of the paper edge because most printers can't print right to the edge.
Can I use a printed ruler for accurate measuring?
For everyday jobs such as ring sizes, shoe sizes, crafts and quick checks, yes, once the card test passes. Paper can stretch slightly with humidity, so for precise work use a real metal ruler.
Can I save the ruler as a PDF?
Yes. Press Print ruler and choose Save as PDF or Microsoft Print to PDF as the printer. When you print the PDF later, keep the scale at 100%.
What do the small lines on an inch ruler mean?
The longest lines mark whole inches, then half inches, quarter inches and eighths, and the shortest lines mark sixteenths. On the centimeter ruler, long lines are centimeters, the middle line is 5 mm and the short lines are millimeters.