Buying a ring without knowing your size is the easiest way to end up with a band that’s too tight or too loose — and rings are the one piece of jewelry that has to fit exactly right. This free printable ring sizer gives you an accurate US size in under a minute: print it, match an existing ring to the circles, and read the number. It works with any printer.
The printable sizer needs JavaScript to draw the circles. Without it, you can still measure the old way: wrap a strip of paper around your finger, mark where it overlaps, lay it flat on a ruler in millimeters, and look up the inside diameter in the chart below.
How to use this ring sizer
- Print it at 100% scale. Before you measure, check the calibration ruler at the top of the sheet — the 50 mm line must measure exactly 50 mm (about 2 inches) with a real ruler, and a standard credit card should fit the outline edge to edge. If either is off, reprint with “Actual size” or “No scaling” selected.
- Match a ring you already own. Lay a ring that fits the intended finger flat over the circles. The circle where the inside edge of your ring lines up exactly with the printed line is your size. This is the most accurate home method.
- Read the size printed under the circle. If your ring sits partway between two circles, you are a half size — e.g. between 7 and 8 is 7.5.
Why measuring beats guessing
Fingers change size across the day — they are smaller when cold and larger at the end of a warm day — so a ring that was “eyeballed” rarely fits the way you hope. A printed sizer removes the guesswork for the one measurement that has no room for error. Wide bands (roughly 6 mm and up) fit tighter, so round up half a size; if you are between sizes on a standard band, round up to the nearest half size.
US ring size chart
If you already know your inside diameter in millimeters, read your US size straight from this chart:
| US size | Inside diameter (mm) | Inside circumference (mm) |
|---|---|---|
| 3 | 14.1 | 44.3 |
| 4 | 14.9 | 46.8 |
| 5 | 15.7 | 49.3 |
| 6 | 16.5 | 51.8 |
| 7 | 17.3 | 54.4 |
| 8 | 18.1 | 56.9 |
| 9 | 18.9 | 59.4 |
| 10 | 19.8 | 62.2 |
| 11 | 20.6 | 64.7 |
| 12 | 21.4 | 67.2 |
| 13 | 22.2 | 69.7 |
Frequently asked questions
How do I measure my ring size at home without a sizer?
Print this page at 100% scale, then lay an existing ring that fits the intended finger over the circles until the inside edge lines up with a printed line. That number is your US size. The chart above converts a measured diameter to a size if you prefer to measure with a ruler instead.
Will my printer change the size?
It can, if the page is scaled to fit. That’s why the sheet has a calibration ruler and a credit-card outline at the top: check them against a real ruler or card before you measure, and reprint with “Actual size” or “No scaling” if they don’t match.
What if my ring falls between two circles?
You are a half size. For a standard band, order the half size between the two (between 7 and 8 is 7.5). For wide bands of about 6 mm and up, round up half a size — they sit tighter on the finger.
Once the ring fits, give it a home you can actually see. Read the free 5-minute jewelry reset guide, or use the jewelry box size finder to match your collection to the right box.