How to find her ring size without her knowing
The most dependable way to find her ring size is to quietly borrow a ring she already wears on that finger and measure it. If you can't manage that, try tracing one of her rings onto paper, asking someone close to her, or making a careful estimate from what's typical for most women.
Size her ring on screen Printable ring sizer
Quiet ways to find her ring size
Here are four discreet options, and asking her isn't one of them:
- Borrow a ring she owns for a few minutes and measure it.
- Make a pencil tracing of a ring's inner circle on paper.
- Check with a close friend or relative who might know her size.
- Estimate using the average women's size.
Borrowing or tracing a ring gives you a real measurement, so start with those. Guessing from the average is the fallback, because it's the least reliable.
Borrow a ring that fits the same finger
Your best bet is to borrow one of her rings, and if you can, choose the one she wears on that same finger.
Once you have it, lay it on the circle in the ring sizer on our home page, which shows her size for you. Then return it before she misses it.
Ask someone close to her
When borrowing a ring isn't an option, Blue Nile recommends you ask a trusted friend or relative for help. Her mum, a sister or a close friend might already know the size. If they do, you might not need to borrow a ring.
It's still worth asking which finger that size belongs to.
Trace one of her rings
Tracing one of her rings gives you a genuine measurement. Lay the ring flat on paper and draw around the inner edge, a method recommended by both Blue Nile and TDF Jewelry. Next, use a ruler to measure straight across your drawing, through the middle, counting the small millimetre marks.
Then find the closest number in this chart, and the size is next to it.
| US | Across the inside (mm) |
|---|---|
| 5 | 15.70 |
| 6 | 16.51 |
| 6.5 | 16.92 |
| 7 | 17.32 |
| 8 | 18.14 |
| 9 | 18.95 |
| 10 | 19.76 |
| 11 | 20.57 |
Estimating a ring size from the average
If nothing else works, the average is your backup plan. TDF Jewelry, a US jeweller, says most women's rings sold are between US 5 and 7. In the UK, most women wear about an M, says the Antique Jewellery Company.
Just remember an average is not her finger, so a ring she really wears will tell you far more.
Making a safer guess at ring size
If you're torn between 2 sizes, go with the larger one. A jeweller can make a ring smaller more easily than bigger, so a ring that is slightly loose is the easier one to fix.
Band width plays a part as well. A wide band feels tighter than a thin one on the same finger, so with a wide ring it's worth considering moving up by half a size.
Frequently asked questions
Is size 7 large for a girl?
No. A US 7 is one of the sizes women buy most, just a little above the middle.
Does size 10 count as big for a woman?
A US 10 is bigger than most women's rings, but plenty of women wear it. What matters is a ring that fits her.
How does a US 7 convert abroad?
If her ring came from another country, a US 7 is called N½ in the UK and 54 in Europe.
How does a US 6 convert in Japan and India?
A US 6 is an 11 in Japan and a 12 in India. In the UK it is an L½, and in Europe a 52.