Ring size chart
US ring sizes with inside diameter and inside circumference. Circumference in millimetres is also the ISO 8653 size used across most of Europe.
| US size | Inside diameter (mm) | Inside diameter (in) | Circumference (mm) / EU size |
|---|---|---|---|
| 3 | 14.1 | 0.554 | 44.2 |
| 3½ | 14.5 | 0.570 | 45.5 |
| 4 | 14.9 | 0.586 | 46.8 |
| 4½ | 15.3 | 0.602 | 48.0 |
| 5 | 15.7 | 0.618 | 49.3 |
| 5½ | 16.1 | 0.634 | 50.6 |
| 6 | 16.5 | 0.650 | 51.9 |
| 6½ | 16.9 | 0.666 | 53.1 |
| 7 | 17.3 | 0.682 | 54.4 |
| 7½ | 17.7 | 0.698 | 55.7 |
| 8 | 18.1 | 0.714 | 57.0 |
| 8½ | 18.5 | 0.730 | 58.3 |
| 9 | 18.9 | 0.746 | 59.5 |
| 9½ | 19.4 | 0.762 | 60.8 |
| 10 | 19.8 | 0.778 | 62.1 |
| 10½ | 20.2 | 0.794 | 63.4 |
| 11 | 20.6 | 0.810 | 64.6 |
| 11½ | 21.0 | 0.826 | 65.9 |
| 12 | 21.4 | 0.842 | 67.2 |
| 12½ | 21.8 | 0.858 | 68.5 |
| 13 | 22.2 | 0.874 | 69.7 |
Each full US size adds 0.032 in (0.81 mm) to the inside diameter, about 2.55 mm of circumference. Half sizes are shown in grey.
Measure an existing ring
Slide the ring onto a ring mandrel without forcing it and read the size at the lower edge of the band. Or measure the inside diameter across the widest point with calipers and match it to the chart.
Size a finger
Use finger sizers of the same width as the ring being made. A sizer should pass over the knuckle with slight resistance and sit without spinning freely. Fingers swell with heat and through the day, so check twice if the result is between sizes.
Wide bands and comfort fit
A wide band feels tighter than a narrow band of the same size, and many jewelers size up a quarter to a half size for bands about 6 mm and wider. Comfort-fit bands, domed on the inside, usually fit closer to true size. When in doubt, size with a gauge as wide as the finished ring.
Mandrels
All mandrels-
Bezel Mandrels
$20.00 Options -
Bracelet Mandrel 36-75mm
$65.00 -
Cylinder Mandrels
$7.50 -
Durston - Wooden Bracelet Mandrel
$29.00
Shop ring gauges, finger sizers and calipers
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