So you’ve decided you want to pop the question — and you’ve started to shop for an engagement ring, but you don’t know her ring size. You don’t have to ruin your surprise proposal to find it out, though. Just get a little bit sneaky and you can figure it out without her knowing you’re about to ask her to marry you.
Go into her jewelry box
Borrow one ring that she wears on her ring finger and take it into the jeweler that day (so you can return it quickly so she doesn’t realize it is missing) so they can check what size she wears. You can also take the ring and place it on a piece of paper and outline both the inside and outside of the ring–if you bring that into your jeweler, they should be able to estimate her ring size accurately.
Ask one of her girlfriends to help you figure it out
If you can trust one to keep your secret, tell one of your girlfriend’s closest friends that you plan to propose and need to figure out her ring size. It is possible she already knows her ring size. If not, she can go shopping with your hopefully future fiance for some rings to find out, or she can find a way to have her try on one of her rings and maybe they’re the same size!
Measure her finger as she snoozes
If your girlfriend is a very sound sleeper, you may be able to figure out her ring size while she’s sleeping. Cut a strip of paper or use a string and carefully wrap it around her ring finger as she sleeps to get a measure of the circumference of her finger. Then, measure it with a ruler. With that number, refer to a ring size chart (you can find one online).