📏 Printable Ruler
Rulers, a tape measure, protractors and a ring sizer that print at true size — with a calibration step so your printer can't shrink them.
1 · What to print
2 · Options
3 · Print
Print the calibration page (or check the 100 mm line on any page). If it measures 98.5 mm, type 98.5 — everything is scaled up to compensate.
💡 Print at Actual size / 100%. Check the 100 mm line with a real ruler or a card: a bank card is exactly 85.6 mm wide. For a sturdier ruler, print on card or glue the strip onto cardboard.
Ring size chart
| US size | Inside diameter | Inside circumference | EU size |
|---|---|---|---|
| 3 | 14.1 mm | 44.2 mm | 44 |
| 4 | 14.9 mm | 46.8 mm | 47 |
| 5 | 15.7 mm | 49.3 mm | 49 |
| 6 | 16.5 mm | 51.9 mm | 52 |
| 7 | 17.3 mm | 54.4 mm | 54 |
| 8 | 18.1 mm | 57.0 mm | 57 |
| 9 | 18.9 mm | 59.5 mm | 60 |
| 10 | 19.8 mm | 62.1 mm | 62 |
| 11 | 20.6 mm | 64.6 mm | 65 |
| 12 | 21.4 mm | 67.2 mm | 67 |
| 13 | 22.2 mm | 69.7 mm | 70 |
Half sizes sit halfway between. Print the ring sizer strip to measure your finger, or lay a ring that fits on the printed circles.
How to check your printed ruler is accurate
Print at Actual size / 100%, then measure the 100 mm check line with a real ruler — or lay a bank card on the calibration page: it is exactly 85.6 × 54 mm. If the line measures, say, 98.5 mm, type 98.5 into “Printer correction” and print again; the tool scales the page to cancel out your printer's error and remembers the setting for next time.
About the Printable Ruler
🎯 True to size
Every page carries a 100 mm check line. If your printer scales a little, enter what you measured and the next PDF is corrected to compensate.
📏 cm, inches or both
Millimetre ticks with centimetre numbers, inch rulers to 1/16 inch, or a dual ruler with metric on one edge and imperial on the other.
🧵 Long tape measures
Lengths longer than the paper print as numbered strips with glue tabs, so you can make a 1.5 m sewing tape or a 60-inch body measure.
◠ Protractors
Half-circle and full-circle protractors with 1° ticks and both inner and outer scales, in three sizes.
💍 Ring sizer
Wrap the strip round your finger to read your US and EU ring size, or lay a ring you already own on the circle chart.
🖨️ Clean vector PDF
Lines are drawn as vectors, so ticks stay sharp and exactly placed on any printer.
Frequently Asked Questions
How do I make sure a printed ruler is accurate?
Print at Actual size or 100% — never "Fit to page". Then measure the 100 mm check line with a real ruler, or compare it with a bank card, which is 85.6 mm wide. If the line is off, type the measured length into "Printer correction" and print again.
Can I print a 30 cm ruler on A4?
A 30 cm ruler is a little longer than an A4 page can print, so it comes out in two pieces with a glue tab that lines them up exactly. On A3 or Tabloid it prints in one piece.
How does the ring sizer work?
Cut out the strip and the slot, wrap the strip round the base of your finger, push the end through the slot and pull it snug. The number at the slot is your size. Measure at the end of the day, when fingers are a little larger.
How are ring sizes worked out?
EU sizes are the inside circumference in millimetres. US sizes follow the standard scale, where each whole size adds about 0.81 mm to the inside diameter (size 7 is about 17.3 mm across).
Why does my printed ruler not match my real one?
Most often the print dialog scaled the page. Turn off "Fit to page", "Shrink oversized pages" and any borderless option. A very small difference can come from the printer itself — use the printer correction box to fix it.
How can I measure my ring size at home?
Print the ring sizer at actual size, cut out the strip and slot, wrap it round the base of your finger and read the size at the slot. Or measure a ring you already own against the printed circles.
Is a printed ruler accurate enough to use?
Yes, once you’ve checked it: printed at actual size and verified against the 100 mm line, it is accurate to a fraction of a millimetre — fine for crafts, sewing and quick measurements.
