Ring sizes for women
Most women wear between US 5 and US 7, with US 6 the average — 16.5 mm inside diameter, 51.9 mm around. Engagement rings are usually worn on the ring finger of the left hand, which is the finger to measure.
Women's ring size chart
| US / Canada | Inside diameter (mm) | Inside circumference (mm) | EU (ISO 8653) | UK / AU (approx.) | Japan |
|---|---|---|---|---|---|
| 3 | 14.1 | 44.2 | 44 | F | 4 |
| 3.5 | 14.5 | 45.5 | 46 | G | 5.5 |
| 4 | 14.9 | 46.8 | 47 | H | 7 |
| 4.5 | 15.3 | 48.0 | 48 | I | 8 |
| 5 | 15.7 | 49.3 | 49 | J | 9 |
| 5.5 | 16.1 | 50.6 | 51 | K | 10.5 |
| 6 | 16.5 | 51.9 | 52 | L | 12 |
| 6.5 | 16.9 | 53.1 | 53 | M | 13 |
| 7 | 17.3 | 54.4 | 54 | N | 14 |
| 7.5 | 17.7 | 55.7 | 56 | O | 15 |
| 8 | 18.1 | 57.0 | 57 | P | 16 |
| 8.5 | 18.5 | 58.3 | 58 | Q | 17 |
| 9 | 19.0 | 59.5 | 60 | R | 18 |
| 9.5 | 19.4 | 60.8 | 61 | S | 19 |
| 10 | 19.8 | 62.1 | 62 | T | 20 |
| 10.5 | 20.2 | 63.4 | 63 | U | 21.5 |
| 11 | 20.6 | 64.6 | 65 | V | 23 |
| 11.5 | 21.0 | 65.9 | 66 | W | 24 |
| 12 | 21.4 | 67.2 | 67 | X | 25 |
| 12.5 | 21.8 | 68.5 | 69 | Y | 26 |
| 13 | 22.2 | 69.7 | 70 | Z | 27 |
EU sizes follow ISO 8653, where the size number is the ring's inner circumference in millimetres. UK letter sizes are the widely used jeweller approximations and may differ slightly from one jeweller to another. Half sizes between whole sizes are interpolated.
Fit tips for women's rings
Thin bands feel looser. A delicate 1.5 mm band at US 6 will feel roomier than a chunky statement ring at the same size. If you are between sizes and the band is slim, the smaller size is often right; if the band is wide, take the larger.
Stacked rings need room. Wearing two or three rings together on one finger effectively widens the band. Plan a quarter to a half size up for rings bought specifically to stack.
Size changes through the day — and the month. Fingers swell with heat, exercise and salt, and many women notice a small cyclical change too. Measure in the evening, and if a ring must be perfect for a fixed date, measure on a few different days and take the most common reading.
Surprise buyers: the average is a starting point only. Better evidence, in order: a borrowed ring measured on the on-screen sizer, a friend or family member who knows, then the averages — and always a resizable setting with a good exchange policy.
Frequently asked questions
What is the most common women's ring size?
US 6 is the most commonly purchased women's ring size, and US 6.5–7 is close behind — together they cover a large share of buyers.
Is US 5 a small ring size?
It is at the smaller end of the usual adult range (roughly US 4–9 for most jewellers' stock), but it is a standard stock size and nothing unusual.
Should an engagement ring fit tight or loose?
It should resist slightly as it passes the knuckle, then sit at the base without spinning on its own. If it spins freely when your hand is cold and dry, it is at risk of slipping off — consider a quarter size down or sizing beads.