Print a ring sizer for A4 or US Letter.
Two print-ready PDFs with 41 quarter sizes, a cut-out finger strip, and bank-card, 50 mm, and 1 inch checks. Print at 100% and verify before measuring.
- 1Print at "Actual size" or 100% — never "Fit to page".
- 2Check the 50 mm line, 1 inch line, and bank-card frame before you start.
- 3Place a ring on the circles; whichever matches its inner edge is your size.
Print calibration: a reproducible check
Reviewed by Belaroq Jewelry & Product Team · · Method version 1
A description of the Belaroq tool and printable method, with worked calculations. Examples are not physical accuracy tests or a guarantee of fit.
Verify the printed references
Suggested print percentage = expected reference length / measured reference length × 100. Reprint and remeasure; do not apply a numerical correction to a finger measurement from an incorrectly scaled page.
| Reference | Expected physical size | Check |
|---|---|---|
| Metric line | 50 mm | Use a ruler; measure between end ticks |
| Inch line | 1 inch = 25.4 mm | Cross-check the same print scale |
| Bank-card frame | 85.6 × 53.98 mm | Check width and height with a standard card |
Worked print example: if the 50 mm reference measures 51 mm, the page is 2% oversized. 50 / 51 × 100 = 98.04% is a suggested reprint scale when starting from 100%. Verify the new printout before measuring.
- Use the PDF matching your paper: A4 or US Letter. Print at Actual size / 100% with Fit to page disabled.
- Measure the 50 mm line and 1 inch line with a physical ruler, then check the bank-card frame in both directions.
- If the reference marks do not match, change print scaling and reprint before using the circles or strip.
- If horizontal and vertical scale disagree, stop using that printout and use another measurement method.
Repeat and record the measurement
- Record three separate measurements for the same finger and hand, removing and repositioning the ring or strip between readings.
- Record the method, raw millimeters, browser zoom or print setting, and the lowest and highest readings.
- Cross-check against an independent method or a professional fitting, especially when readings map to different sizes.
- Confirm the intended band width, knuckle passage and comfortable fit with Belaroq before production; do not average away conflicting readings.
The tool selects the nearest supported row of the shared ring-size chart. EU is rounded inner circumference in millimeters. Numerical step size and quarter-size labels are not a measurement-accuracy claim.
A 1 mm error in measured inner diameter changes the calculated circular circumference by about 3.14 mm. This geometric relationship is not a tolerance or a measured error range for the tool.
Suggested citation: Belaroq. Print calibration: a reproducible check. Method version 1, reviewed 2026-09-30. Canonical method and worked example.
Reference sources: GIA: Ring size guide and chart; NIST: The inch is exactly 25.4 millimeters. The reference sources do not certify or validate the Belaroq tool.
Ring placed on the printed sizer? Take a photo and the AI reads the matching size for you.
The photo should show the ring on the circles with labels visible. Print at 100% and verify the 50 mm line, 1 inch line, and bank-card frame first.
Printing questions
How do I print the sizer at the correct scale?
Choose the PDF that matches your paper, then print at Actual size or 100%—never Fit to page. Before measuring, verify the 50 mm line, 1 inch line, and bank-card frame.
How do I use the printed sizer?
Place a ring that fits on the circles until its inner edge matches one. The size printed under that circle is your size. To measure a finger, use the cut-out paper strip.
Does it work on both A4 and Letter paper?
Yes. Download the dedicated A4 or US Letter version, print at 100%, and check all three scale references before use.
Use your measured size for a custom diamond ring
Convert the measured inner diameter or circumference with the US, UK, EU and JP ring size chart. For a custom lab-grown diamond ring, record your US size, measured millimeters and band width, then confirm the fit before production. The ring sizer tutorial explains the second-method check.