Printable Ring Sizer
Print a true-to-scale paper ring sizer strip and a ring circle chart to find your ring size at home. A 50 mm calibration square and bank card outline confirm the printout is the right size, and you can correct for a printer that scales the page.
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Print at 100% / Actual size with “Fit to page” turned off.
How to use the Printable Ring Sizer
- Choose the size labels (US, UK or EU), the paper size and how many strips you want.
- Download the PDF and print it at 100% / Actual size with Fit to page turned off.
- Measure the calibration square: it must be exactly 50 mm. If not, enter what you measured and print again.
- Use the strip: cut it out, cut the slit, wrap it around the base of your finger and read the size at the slit.
- Or use the circles: lay a ring that fits well on the chart and pick the circle whose line just shows inside the ring.
Ring size chart: US, UK, EU and diameter
The table uses the standard US formula (inside diameter = 11.63 mm + 0.8128 mm × size). EU sizes are the inside circumference in millimeters, rounded; UK letters follow BS 6820 (A = 37.5 mm, +1.25 mm per letter). Japanese sizes are approximately the circumference minus 40.
| US / Canada | Inside diameter | Circumference | UK / AU | EU / ISO | Japan |
|---|---|---|---|---|---|
| 3 | 14.07 mm | 44.2 mm | F½ | 44 | 4 |
| 4 | 14.88 mm | 46.8 mm | H½ | 47 | 7 |
| 5 | 15.69 mm | 49.3 mm | J½ | 49 | 9 |
| 6 | 16.51 mm | 51.9 mm | L½ | 52 | 12 |
| 7 | 17.32 mm | 54.4 mm | N½ | 54 | 14 |
| 8 | 18.13 mm | 57.0 mm | P½ | 57 | 17 |
| 9 | 18.95 mm | 59.5 mm | R½ | 60 | 20 |
| 10 | 19.76 mm | 62.1 mm | T½ | 62 | 22 |
| 11 | 20.57 mm | 64.6 mm | V½ | 65 | 25 |
| 12 | 21.38 mm | 67.2 mm | X½ | 67 | 27 |
| 13 | 22.20 mm | 69.7 mm | Z+1 | 70 | 30 |
Jewelers' charts differ slightly, especially for UK letters and Japanese sizes, so treat neighboring sizes as a range and check the seller's own chart when you can.
Getting an accurate reading
- Print settings matter most. Browsers and PDF viewers often shrink pages 3–6% to fit the printable area, which can shift the result by a whole size. Always check the 50 mm square.
- Snug, not tight. The strip should slide over the knuckle with a little resistance. Pulling it hard reads half a size or more too small.
- Measure the right finger. Dominant-hand fingers are often slightly larger, and the same finger can differ between hands.
- Wide bands fit tighter. For bands 6 mm or wider, choose about half a size up from your reading.
- Use thicker paper. Card stock stretches less than copy paper and gives more consistent results with the strip.
Frequently asked questions
How do I make sure the printable ring sizer is the right size?
Print at 100% or Actual size with Fit to page, Shrink to fit and Scale to fit turned off, on paper that matches the size chosen here. Then measure the calibration square with a ruler: it must be exactly 50 mm on every side. You can also lay a credit, debit or ID card on the card outline; it should match exactly. If the print is off, the ring sizes will be off too.
What if my printer prints the square at 49 mm?
Enter 49 in Measured square and print again. The sheet is then drawn about 102% larger, which cancels out the printer's shrinking so the next print comes out at 50 mm. Measure again to confirm. The correction is limited to 45–55 mm because a larger error means a print setting is wrong.
How do I use the paper ring sizer strip?
Cut out the strip and cut along the dashed slit. Wrap it around the base of the finger with the numbers facing out, push the pointed end through the slit and pull it until it is snug but still slides over the knuckle. The number at the edge of the slit is your size. Measure two or three times for a consistent result.
How does the ring circle chart work?
Each circle is drawn at the inside diameter of one US size, from 3 (14.07 mm) to 13 (22.20 mm) in half sizes. Put a ring that already fits the right finger on the circles. The correct size is the one where the ring's inside edge sits right on the outside of the line, with the line just visible inside. If it falls between two circles, choose the larger.
How are US, UK and EU ring sizes calculated?
A US or Canadian size has an inside diameter of 11.63 mm plus 0.8128 mm per size, so size 7 is 17.32 mm across. EU / ISO 8653 sizes are the inside circumference in millimeters (size 7 is about 54). UK and Australian sizes are letters: A is 37.5 mm in circumference and each letter adds 1.25 mm.
When is the best time to measure ring size?
Measure at the end of the day when your fingers are warm, because fingers are smaller in the morning and in the cold and can swell slightly in heat. A ring must also pass over the knuckle, so if your knuckle is large, measure it too and choose a size that fits over it. For wide bands (6 mm or more), go up about half a size.
Is a printed ring sizer accurate enough to order a ring?
A correctly printed sizer is usually accurate to about half a size, which is fine for most purchases. Paper can stretch slightly and strips can be pulled too tight, so measure several times. For an expensive or hard-to-resize ring, confirm with a jeweler's metal sizer.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.