How Do I Know Her Ring Size?

Your surprise proposal may be foiled by a tiny, but very important detail: you don’t know what size to make the engagement ring.

We memorize our shoe size, our inseam length, even our hat size if we’re into that kind of thing — but ring size is not a measurement many of us think about until we have to.

And yet, it’s one of the most important details when buying an engagement ring. Depending on the type of ring you buy, having it re-sized can be troublesome. Re-sizing  a plain gold band won’t be a tough job for any professional jeweler, but as you get into harder metals, such as platinum or if you select a band with diamonds all the way around it, re-sizing can be very difficult, expensive or even impossible.

You also don’t want to have to return the ring to the jeweler after you surprise your fiancée with it. The ring is in the spotlight after an engagement, and you and your fiancée will feel disappointed when you announce the big news and then have no ring to show for it.

But finding her ring size secretly can be tricky. Here’s a ring sizing guide that can help you size things up and still keep your secret.

Grab another ring

If only it were this easy! If your fiancée-to-be wears a ring on her left ring finger, you can borrow it, secretly of course. If it’s a ring she doesn’t wear often, it should be no problem to remove it from her jewelry box and take it to a jeweler to determine size, or use our online ring size tool to compare.

But if she wears it every day, you’ll need to be sneakier than that. Press the ring into a piece of clay or bar of soap. Then take it to your jeweler, who will produce a keychain of ring sizers to compare to the impression. You can also try it on and see where it hits you on your own finger.

Remember: it’s very important you compare a ring that she already wears on the same finger and hand. Humans are imperfect, and our fingers can be different sizes on different hands.

Tie the knot (literally)

Wrapping a piece of string around her finger and tying a knot or bow can help you find out her ring size. You can do this while she’s sleeping, or figure out a way to do it so she thinks you’re being funny.

Crash the girls’ night out

Ask her married or engaged friends to pass around their rings for people to try on. Have one of them observe what ring fits your fiancée-to-be.

Go to a festival

If you’re at an art festival or flea market or somewhere else with costume jewelry rings, act like you’re fooling around and start slipping on gaudy cocktail rings — and encourage her to do the same.

Most rings, even those with diamonds or gems in the shank, can be sized up or down one size — though after that, it starts to compromise the integrity of the setting. Stones could fall out or get damaged. But if you’re really in doubt, it may be best to compromise and take her to the jewelry store with you. Even if she’s not blown away, at least she’ll have an engagement ring that’s a perfect fit — in more ways than one.