Ring Size Guide
How to find her size without asking
The short answer: borrow a ring she already wears on her left ring finger and measure the inside diameter. Everything else here is a backup plan.
Six ways to find out
Borrow a ring she owns
ExcellentMeasure the inside diameter of a ring she already wears on her left ring finger.
Trace the inside
GoodSet the ring on paper, trace around the inside edge, and measure the diameter of the circle.
Recruit her friend
ExcellentAsk someone close to her — there's a decent chance she already knows.
String trick while she's asleep
FairWrap a piece of string around her finger and measure the circumference. Works, but risky if she wakes up.
Buy an inexpensive ring first
GoodTest the fit months ahead with a cheap placeholder ring, then order the real one once you know it's right.
Just ask her
PerfectA direct question about ring size doesn't spoil an engagement surprise. Most people don't put it together.
Size chart
| US Size | Diameter (mm) | Circumference (mm) |
|---|---|---|
| 4 | 14.9 | 46.8 |
| 4.5 | 15.3 | 48.0 |
| 5 | 15.7 | 49.3 |
| 5.5 | 16.1 | 50.6 |
| 6 | 16.5 | 51.9 |
| 6.5 | 16.9 | 53.1 |
| 7 | 17.3 | 54.4 |
| 7.5 | 17.7 | 55.7 |
| 8 | 18.1 | 57.0 |
| 8.5 | 18.5 | 58.3 |
| 9 | 18.9 | 59.5 |
| 9.5 | 19.4 | 60.8 |
| 10 | 19.8 | 62.1 |
| 11 | 20.6 | 64.6 |
| 12 | 21.4 | 67.2 |
Her size is not one number
Temperature, time of day, diet, exercise, and even how much salt she had for dinner can shift finger size slightly. Measure at room temperature, ideally in the evening when fingers are at their largest.
Band width and knuckle prominence matter too — a wider band fits more snugly than a thin one at the same size, and a prominent knuckle may need a size up from what the base of the finger suggests. When in doubt, size up: it's easier to resize a ring down than up, and Celino resizes for free, for as long as you own the piece.
Straight answers
What if I get the size wrong?
Free resizing for as long as you own the piece — no charge, no time limit. Getting close is enough; we handle the rest.
Which finger should I measure?
The left ring finger, if that's the hand the ring will be worn on. Ring size can differ noticeably between hands and even between fingers on the same hand.
Can I just guess based on my own ring size?
Not reliably — even close relationships tend to be off by a size or more. Use one of the methods above, or just ask her.