Printable Ring Sizer
A cut-out paper strip for measuring your finger circumference — with a built-in check so you can confirm it printed at the correct scale before you trust it.
When the print dialog opens, set Scale to 100% / Actual size (not "Fit to page") — then check the calibration box below with a ruler before trusting the strip.
Your printable ruler strip
Print, calibrate, then cut.
Calibration check — do this first
↔ Width: 50mm
Measure the square above with a ruler or tape measure — check both its width AND its height. Each must be exactly 50mm (2 in). If either measurement is off (even if the other one is correct), your print scale wasn't set to 100% — go back, set Scale to 100% / Actual size, and print again before using the strip below.
Cut-out ruler strip
How to use it
- Click "Print this sizer" above, or use your browser's Print command (Ctrl/Cmd + P).
- In the print dialog, set the scale to 100% or "Actual size" rather than "Fit to page".
- With a ruler or tape measure, check the calibration square on the printout — measure BOTH its width and its height, each must be exactly 50mm (2 in). If either measurement is off, reprint at the correct scale before continuing.
- Cut out the ruler strip along the dashed line.
- Wrap it snugly around the base of your finger and note where it overlaps itself.
- Read the millimeter mark closest to that point, then enter it into the "I measured my finger" mode on the ring size calculator.
Why the calibration check matters
Printers and PDF viewers don't always print at true 100% scale — a document set to "fit to page", or printed on a different printer than expected, can shrink or stretch the ruler enough to throw off a measurement by a size or more, without any obvious sign that something's wrong. Some printers even scale width and height by different amounts, so checking only one dimension of the calibration box could miss the problem — that's why the calibration square is checked on both axes. Checking it with a physical ruler first catches that problem before it affects your result. Prefer not to print anything at all? The on-screen card-calibration tool on our measuring guide works entirely on your screen instead.
Frequently asked questions
How do I know if my printed sizer is accurate?
Check the calibration square on the printout with a ruler or tape measure — measure BOTH its width and its height, each must be exactly 50mm (2 in). Checking both matters because some printers scale width and height by different amounts, so one dimension can be correct while the other is off. If either measurement is wrong, your printer didn’t use 100% scale; go back, set Scale to "100% / Actual size" in the print dialog, and print again before trusting the ruler strip.
What if I don't have a ruler to check the calibration box?
A standard credit or debit card is 85.60mm wide (the international ISO/IEC 7810 ID-1 size), so you can compare it against the calibration box as a rough double-check. Or use the on-screen calibration tool on our measuring guide instead — it doesn’t require printing anything.
Is a printed paper sizer as accurate as a real ruler?
Treat it as a convenient alternative for when you don’t have a ruler on hand, not a replacement for one. A physical ruler, tape measure, or the calculator’s "I have a ring that fits" mode is generally more reliable.