Printable Ruler (cm, mm & Inches)
This is a genuinely usable ruler — every tick is placed from real millimeter measurements in the page itself, not an image that might get rescaled. It doubles as a quick calibration check: the pink 100mm bar should measure exactly 10cm (or 3.94in) with an actual ruler once printed. If it doesn't, your print dialog is scaling the page instead of printing at true size.
If the button doesn't work, press Ctrl+P (Windows/Linux) or Cmd+P (Mac) to open your browser's print dialog.
This is an on-screen preview. Your printer, paper, ink or toner level, and print driver settings all affect the final physical result.
How to use this printer test
- In your print dialog, set scale to 100% and turn off "Fit to page" or "Shrink to fit" — either of those will silently resize the ruler.
- Choose your paper size above; landscape orientation gives you a longer ruler edge on the same paper.
- Print on plain paper.
- Check the pink 100mm reference bar with any ruler you already trust — it should measure exactly 10cm.
What should the printed page look like?
The 100mm bar measures exactly 100mm
This is the single fastest way to catch a scaling problem. If it measures anything other than 100mm (10cm), your printer or print dialog is scaling the page, and every measurement on this ruler — and on anything else you print at "actual size" — will be off by the same proportion.
Cut along the edge for a working ruler
If the calibration bar checks out, you can trim the sheet along the printed edge and use it as a genuine ruler — the tick marks are placed from the actual page geometry, not scaled from an image.
Consistent spacing across the full length
Check a few points along the ruler, not just the start — some printers apply a slightly different scale across a long axis, especially on rollers or older mechanisms, which a single measurement near the edge won't catch.
Common printer problems
The 100mm bar measures slightly more or less than 100mm
Likely cause: "Fit to page" or a similar auto-scale option is enabled in the print dialog, or the printer driver has its own default scaling applied.
How to fix it: Explicitly set the print scale to 100% (sometimes labeled "Actual size") and disable any "fit" or "shrink to fit" option before printing again.
The ruler is noticeably off only in one direction (e.g., width is fine, height is off)
Likely cause: Some printers apply slightly different scaling on each axis due to how the paper feed mechanism advances the page versus how the print head moves across it.
How to fix it: Run our Paper Margin & Scaling Test for a more detailed breakdown of scaling by axis, and check your driver for separate horizontal/vertical scale settings if it offers them.
Frequently asked questions
Can I actually use this as a real ruler?
Yes, as long as the 100mm calibration bar measures exactly 100mm after printing. If it does, cut along the printed edge and the tick marks are accurate to the page's real millimeter geometry.
Why does my printed ruler come out slightly the wrong size?
Almost always a scale setting — "Fit to page" or a similar auto-scale option resizes the whole page, ruler included. Set the print scale explicitly to 100% and disable any fit-to-page option.
Does this ruler include both metric and imperial units?
Yes — a centimeter ruler and an inch ruler (down to 1/16in) across the top, plus a vertical centimeter scale along the left edge.
How do I print a ruler at actual size?
Print with the scale set to 100% or Actual size — not Fit to page or Shrink to fit, which resize the page and make the ruler inaccurate. Then measure the 100mm bar with a known-good ruler: it should be exactly 10 cm (3.94 in).
Is there a millimeter ruler on this page?
Yes. The centimeter ruler has a tick at every millimeter, with longer ticks at 5 mm and numbered centimeters, so you can read millimeters directly. The inch ruler is marked in sixteenths of an inch, and a vertical centimeter scale runs down the page.
Which paper size gives the longest ruler?
A3 in landscape gives the longest ruler, about 38 cm, followed by Ledger. On A4 in landscape the ruler is about 25 cm long, and on Letter in landscape about 23 cm. Choose a size your printer actually supports, and use landscape for the longest edge.
How do I make a sturdy ruler from the printout?
Print on thicker paper or cardstock if your printer supports it, or glue the printed sheet to thin cardboard before trimming along the edge. Check the 100 mm bar again after trimming, since cutting off the wrong amount at the start changes where your measurements begin.
How accurate is a printed ruler?
If the 100 mm bar measures exactly 10 cm, a printed ruler is typically accurate to about a millimeter, which is plenty for everyday measuring, sizing a photo or checking a hem. For woodworking, engineering or anything with tight tolerances, use a steel ruler or a caliper instead.