Ruler Online Free

Printable Ruler PDF — Inches and cm

Download a free printable ruler in inches and cm, or a protractor. Every ruler prints true to scale at actual size — choose A4 or Letter to match your paper, then follow the print instructions below.

12 inch / 30 cm ruler preview

12 inch / 30 cm ruler

Full-length ruler with centimeter and 1/16-inch markings. Laid out diagonally so the whole length prints at true size on one page.

8 inch / 20 cm ruler preview

8 inch / 20 cm ruler

Compact horizontal ruler with centimeter and 1/16-inch markings — fits across the page.

Protractor preview

Protractor

180° protractor with inner and outer degree scales and a center mark for measuring and drawing angles.

Print instructions

For accurate printing:

  1. Set page scaling to None / Actual Size (100%).
  2. Use the correct paper size (A4 or Letter) for the PDF you downloaded.
  3. Do notuse “Fit to Page” or “Shrink oversized pages”.
  4. Verify with a real ruler after printing, and reprint if the scale is off.

Frequently asked questions

How do I print a ruler to scale (actual size)?+

Download the PDF, then in your print dialog set scaling to None / Actual Size (100%) and turn off 'Fit to Page'. Choose the matching paper size (A4 or Letter). After printing, check it against a known object so it's true to scale.

Which printable ruler should I choose, A4 or Letter?+

Pick the PDF that matches your printer's paper. Use A4 (210 × 297 mm) outside North America and Letter (8.5 × 11 in) in the US and Canada. The ruler prints at the same true size either way.

Are the printable rulers in both inches and cm?+

Yes. Every printable ruler has a centimeter/millimeter scale on one edge and an inch scale (with 1/16 subdivisions) on the other, so you get inches and cm on a single ruler.

Why does my printed ruler measure slightly wrong?+

Almost always because the printer scaled the page. Reprint with scaling set to 100% / Actual Size and 'Fit to Page' disabled. A diagonal layout is used for the 12 inch / 30 cm ruler so the full length fits on one page at true size.