The ring is meant to be a surprise — so how do you find her size without giving it away? Here are seven stealthy, proven methods, from foolproof to clever guesswork.
1. Borrow a ring she already wears
The most reliable method. "Borrow" a ring she wears on the ring finger of her right hand (closest to the left ring finger) for a day. Then measure its inside diameter in mm and match it on our ring size chart, or trace the inside circle on paper.
2. The soap or clay impression
Press one of her rings into a bar of soap, clay, or play‑dough to leave a clean imprint. Measure the inside diameter of the impression later. Great when you can only borrow the ring for a few minutes.
3. Trace it on paper
Place her ring on paper and trace the inside edge carefully, then measure that circle's diameter. Snap a photo with a ruler next to it so you have a record.
4. Ask a friend or family member
Her best friend, sister or mum often knows her size — or can ask casually ("we were ring shopping for fun, what's your size?") without raising suspicion.
5. Compare against your own finger
Slip one of her rings onto your own finger and mark how far down it goes. A jeweler can size from that reference mark.
6. Go "ring shopping for fun"
Try on costume rings together at a shop "just for fun" and note which fits. Many couples do this casually long before a proposal.
7. Default to the average (last resort)
If all else fails, the average women's size is US 6 to 6.5. See average ring size for women and men for the typical range. Pick an easily‑resizable plain band and size slightly up.
The golden rule: size up if unsure
A ring that's a touch loose can be resized down quickly; one that won't slide over the knuckle can't be worn on the big day. When in doubt, go slightly larger. Once you have a measurement, confirm it with the ring size calculator.