I'm looking for a subtle way to figure out my girlfriend's ring size. The most common advice you can find by Googling is:

  1. Take the size from a ring that she already wears
  2. Ask her


  1. She doesn't wear rings
  2. It's supposed to be a surprise

I've been racking my brain with James Bond style ways to get her ring size, but I think lassoing her finger in the middle of the night might be a bit suspicious. Any ideas?

For obvious reasons, I'm staying anonymous.

  • 20
    I'de like to use the phone a friend lifeline Commented Dec 17, 2015 at 19:14
  • 90
    I know it is The Thing You're Supposed To Do In This Culture, but surprising your SO with a proposal, ring in hand, etc. is a rotten thing to do to someone; it makes it too hard for them to say no. Have an honest and non-scripted conversation about whether the two of you actually want to get married. Then, if you are going to get married, go pick out rings together. I promise you everything will be easier this way.
    – zwol
    Commented Dec 18, 2015 at 15:49
  • 20
    @zwol that happens to be what my wife and I did, and I can honestly say she would have rather I surprised her. It isn't always a rotten thing to do. Regardless, this is useful for any kind of ring, not just an engagement ring.
    – corsiKa
    Commented Dec 19, 2015 at 0:21
  • 17
    @zwol yes, have enough conversations about potential marriage that you know you're on the same page. Make sure her parents are OK with the idea too. But no, don't make the final decision like that with all the romance of a local government committee meeting. Leave room for it to be a little bit of a surprise whether you're really going to propose, and exactly when and how. Make it surprising, special and memorable. Pick out wedding rings together.
    – jez
    Commented Dec 19, 2015 at 19:05
  • 12
    This question is protected so I can't provide this as a proper answer, but I feel the desparate need to tell you this trick. Wait until nobody is around, then unscrew some of the christmas crackers until you find one with one of those plastic rings inside. Print off a ring measuring thing from the internet and measure the plastic ring. Put the ring back and make sure that you and your wife pull that exact cracker at dinner and make sure she tries the ring on. Jokingly ask her if it fits ok or if it's too small/big. Based on your observations, make an educated guess at a ring size to go for.
    – Pharap
    Commented Dec 20, 2015 at 15:42

18 Answers 18


Ask Her Best Friend or Mother

Especially if this is an engagement situation, ask her best friend or her mother if they know her ring size. If you've been dating seriously for awhile, you'd be surprised how often this type of thing comes up. If neither of them know her ring size, they will likely be more than happy to get in on the intrigue. They can (more easily than you) find out her size under the guise of buying a gift or some other type of conversational pretense like "damn, you really need to know such things just in case, y'know?" Of course, all oaths of secrecy apply.

The Solo Scenario

If you decide to go with this on your own — when you are buying a ring from a jeweler, you typically buy the ring in their "standard" size; I believe it is usually a size 7. Display case rings are typically made a bit larger by design because they want a prospective buyer to be able to see it on their finger; that plus it is typically less destructive to resize the ring smaller than to try and make it bigger later.

Ask the jeweler about the design of the ring and if knowing the ring size is more or less important than sizing it later. If the shank is plain (the part that wraps around the bottom), re-sizing is easy. If it's too big, they simply slice out a small portion at the bottom and join the ends seamlessly. If it's too small, the metal can be heated and stretched, but the thickness of the band will determine how much they can size it before more material has to be added. Adding material can leave a slight line between the old and new metal, so it is better get the bigger ring.

If the ring shank is more ornamental (encrusted with diamonds or something), the ring size is sometimes best known before the ring is even made. That may be a factor in your decision about which ring to purchase. Ask the jeweler.

  • 1
    When I and my then fiancee were buying our wedding rings the jeweler told us that while it is possible to change the size of the ring both ways it's best to get the right size the first time because any later change weakens the ring.
    – Maurycy
    Commented Dec 18, 2015 at 14:58
  • Agreed with Maurycy, although you can get a "standard" size its always best to get the correct size from the get-go. Case and point, I went to get an engagement ring, and they recommended '6' before I said her ring size. She was a 3.5, and if I had gotten the ring, they would not be able to resize to 3.5, which would have to be a special order. So depending on the specific jeweler, you may have some problems (not available in the correct size, the ring given cannot be resized, etc). Commented Dec 18, 2015 at 17:12
  • 43
    I second the "ask her friend" option. When I proposed to my wife, I asked a mutual friend to find out (the day I needed to purchase the ring). She told my wife that she just received a bunch of rings from her aunt that didn't fit her and asked what my wife's size was. When my wife gave her size, she responded with, "That's a shame; you're the same as me!" Worked perfectly and she had zero suspicions!
    – Shadow503
    Commented Dec 18, 2015 at 18:35
  • 1
    Her best friend could take her out shopping, and have her stop by a jewelry store to try on some rings and find out her ring size along the way. If her friend can pick up on what she likes or dislikes in engagement rings, even better. Commented Dec 18, 2015 at 22:37
  • 2
    @ByronJones That's how I did it. Got both her sisters in on the plot, when the 3 of them went on their annual "Sisters day out shopping spree". She turned out to be a size 5, while my best guess (made from a photograph of her hand with a known-size object next to it) had been a 6.
    – Tonny
    Commented Dec 20, 2015 at 14:12

If she is a sound sleeper you can try to measure with a printable paper ring sizer. TIP: do not leave the paper in the trash when done. She will see it!

  • 4
    This. It's how I got my wife's size for her engagement ring. Worked perfectly :) Commented Dec 18, 2015 at 17:39

Hide it in plain sight.

Send her an email telling her you want to ask a personal question, to help you pick a gift, but you don't want to give things away to her, so you are asking a ton of questions.

Then ask her everything you can think of that's size or color or clothes style related

  • Wrist size for bracelelts
  • Bra size
  • "measurements'
  • Ring size of each finger, on both hands
  • clothing sizes, (including petite, or slim or whatever other
  • inseam
  • shoe size
  • Favorite color (if you don't knwo it already)
  • Colors she hates
  • loved or despised syles of clothing (Does she hate capris? Bell
  • Favorite brand of eye makeup
  • Favorite music
  • Favorite flower type
  • Hated flower type (if any)
  • Home delivery address
  • work delivery address (Sending flowers to her at work is an automatic 2x multiplier!)
  • Favorite stuffed animal
  • Favorite bands
  • Favorite kinds of music


Now here is the clever part. Create a file on your docs area of your hard drive, called "(her name) important bio information", and save every bit of this information... If she's a keeper, you'll be referring to this file every Xmas, valentines, and Birthday for years to come.

Every one add more things to ask in the comments please

  • 69
    If you ask her about her eye color, you'll be in serious trouble.
    – Dennis
    Commented Dec 19, 2015 at 12:57
  • 18
    As soon as she gets to "ring size" the jig is up. No one asks ring size, unless its very specifically for a ring.
    – user2742
    Commented Dec 20, 2015 at 21:59
  • 26
    If you have to ask home address, it's probably too early to buy a ring of any sort.
    – FreeMan
    Commented Dec 21, 2015 at 20:23
  • 9
    I've been married more than 25 years now, and after reading this I'm seriously considering it. To be fair, after a quarter of a century I have figured out 4 or 5 of them...
    – T.E.D.
    Commented Dec 23, 2015 at 16:39
  • 9
    I'd recommend going through at least one of the decoys before popping the question. Once the bouquet of flowers shows up at the office, she'll know the question about the ring was just a decoy. Commented Dec 24, 2015 at 4:55

Cunningham's Law: Guess wrong.

"Hey sweetie, I read that your shoe size divided by two plus three is your ring size. It's true for me, what about you?"

"No, my shoe size is X and my ring size in Y"

  • 25
    And how many people do you know that actually know their ring size?
    – Chenmunka
    Commented Dec 18, 2015 at 9:00
  • 23
    @Chenmunka: Indeed; and more on the point: how many people do you know who own no rings who know their ring size? The assumption of the problem is that the girlfriend does not own any rings. Commented Dec 18, 2015 at 17:35
  • 1
    @EricLippert Just because she doesn't currently own a ring doesn't necessarily mean she's never owned or tried on a ring before. I've gone ring shopping before in previous relationships. I've also made the mistake of going into jewelers while window shopping and they practically beg you to try things on.
    – cimmanon
    Commented Dec 19, 2015 at 19:28
  • 2
    @cimmanon: Indeed. The question is not "is it a logical necessity that someone who owns no rings has their ring size memorized?" but rather "is the suggested technique likely to work?" By way of analogy: do you know your hat size? Have you ever tried on a hat? I own a great many hats, have tried on many more, and I do not bother to memorize my hat size. I find it hard to imagine that someone who owns no hats would know their hat size at the drop... just off the bat. Commented Dec 19, 2015 at 20:31
  • 3
    @EricLippert I think you underestimate what a woman might remember about what size she is :-). I haven't purchased or tried on a ring in 20 years (and I've only purchased 4 rings ever), yet I know the size of both my ring finger and my middle finger. Unlike shoes or hats, rings don't usually come with the size printed on them, so owning one isn't even a guarantee that you know what size it is. Meanwhile, my husband doesn't even know his own shoe size.
    – cimmanon
    Commented Dec 19, 2015 at 20:45

Play the "How well do we know each other?" Game

Find one of those "how well do you know your partner" quizzes on the Internet1. Make sure the quiz is something you can download and print out. But before you print it, insert your own question asking what your partner's ring size is. Make sure the tone of the rest of quiz matches that type of question so it sort of blends in with the rest. Longer quizzes will incur less scrutiny on its contents.

The "I don't know" Contingency

If she doesn't know the answer to her ring size, act surprised. Amazed even. "I thought everyone knew their ring size!"

Then bring it up again very matter-of-factly later. You can have a high school ring or something stashed away in the closet somewhere; preferably too small for you (borrow one from a friend if you have to and have it measured by a jeweler).

"Here, try this. It doesn't fit me anymore, but I think it's a size 5 (or whatever) … Okay, there ya go."

And then drop it.

If the ring fits, you'll know the size. If it's a bit too big or a bit too small, you're in the right ballpark. You can try on some ring sizers later at the jeweler to narrow down (on yourself) just how much the ring size seemed too big/small on her finger earlier.

Corny, but it will get you in the right ballpark.

(1) Of course, I bear no responsibility for injury (emotional or physical) for having failed any relationship quiz recommended herein.

  • 2
    Other "for fun" activities or games might be possible to pull off as well. Pottery or Painting: see if you can get a hand-print in there. (Not as accurate, since you only really have width, but better than nothing). "Minute to win it" type scenarios involving making a mold of her finger or "lassoing" and marking it for you in some way. Baby-sit somebody's children for a night and have everyone make play-dough hand molds.. Not the best ideas but maybe the brain storm will knock some better ones from others. Commented Dec 17, 2015 at 19:42
  • If you're going to go the class ring route, I recommend finding a female accomplice and a bit of yarn. When high school couples swap class rings, the girl will sometimes wrap the boy's ring with yarn so that she can wear it on her hand. The female accomplice is so that she can wear the ring after you've added the yarn to give it an authentic "worn in" look (oh look, I forgot to take the yarn off after Betty and I broke up).
    – cimmanon
    Commented Dec 25, 2015 at 3:37
  • I like the disclaimer. Hahahaha
    – Jem Eripol
    Commented Sep 30, 2017 at 7:55

I ran through various options before I proposed last year, and none of the standard advice worked (measure a known-good ring, ask a friend...)

I went with: wait until she is tired and drunk, absent-mindedly play with a bit of string, wrapping it around fingers and so on, and just happen to score the string with my thumbnail when it's on the right finger.

Mirabile dictu, it worked and she didn't notice. Not sure if I'd recommend it in general, though.


You can compare your fingers with her maybe your smallest one would be like her suitable finger. Or If you wear a ring you can try to put it in her finger and see the difference

  • 1
    yeah, I was gonna say hold her hand, locking fingers, and compare her ring finger with your little finger. buy the ring based on that comparison, erring on the "large" side, because the ring can always be reduced easily. Commented Dec 25, 2015 at 4:36
  • 1
    I did exactly this back then, and it worked perfectly :)
    – sfThomas
    Commented Jan 28, 2016 at 21:06

The cunning plan I devised was to get buy my (then) girlfriend a cheapish ring, and give it to her as a anniversary/christmas/birthday gift. Which would have annoyed her quiet significantly, with her being disappointed that it was not engagement ring. But she would have forgiven me.

Then if it was the wrong size, take her to the jeweller to get the cheapish ring resized. and make sure the jeweller would take note of the new size. Which I would then use to get the engagement ring to give her a month or so later.

Before I could swing my cunning plan into action, she took me aside, gave me a plastic ring that fit her, and told me basically: "You are going to ask me to marry you; and if you don't do it by the 29th of February, there will be trouble."

Still I maintain my plan would have worked. Congratulations BTW.

  • 3
    Sounds like you dodged a bullet there. Commented Dec 25, 2015 at 7:01

This is a refinement of the 'compare your fingers' idea, but is considerably more accurate and only requires a photograph:

  1. Find a high-resolution photograph of the two of you where both hands are visible and in close proximity (to ensure there is no foreshortening due to perspective effects).

  2. Crop the photograph to the portion containing your fingers. Enlarge and print onto paper.

  3. Measure (using a ruler) the image diameter of your finger on the photograph (call it a1) and the same measurement of your partner's finger (call it a2). These will depend on how zoomed-in the photograph is.

  4. Determine the actual diameter (d1) of your own finger by discovering your own ring-size and using a conversion table such as http://www.onlineconversion.com/ring_size.htm.

  5. Calculate the actual diameter d2 of your partner's finger by the formula d2 = a2 * (d1 / a1).

  6. Convert this into your partner's ring-size by the same conversion table used in step 4.

The result should be accurate to within a fraction of a millimetre (so you'll be able to determine exactly which US ring-size is closest to your partner's).

EDIT: I actually tried this out shortly after posting the answer. In particular, I designed a ring and had it rendered in platinum. The following image is proof that, at least on this occasion, the method indeed worked as intended:

Ambigram ring

This was eight months ago, and my girlfriend and I have been together ever since...


I had a ring custom made recently and was told it is easier to size a ring up than down. So don't get one too big! My advice is, don't get her a ring. 1. If it's "just a ring" not an engagement ring, she may be confused and either disappointed or scared off depending on how she feels about an engagement. If it is an engagement ring, consider that she will wear this every day and may want a say so in what it looks like. Instead, why not buy her a diamond or other stone. You can get it in a holder that looks sort of like a ring and comes in a ring box. You provide the rock and let her decide on the setting!


If you want to completely minimize the risk of her suspecting you're buying a ring, you can get a rough idea just by holding her hand and trying to remember how it feels. Then compare that sense impression against your sister, mother, friends, your own fingers (pinky, perhaps?) and those of the ring salesperson.

Err on the size of being too big. If she says yes, at least you won't draw blood cramming it onto her finger. Then get it resized as necessary. If all else fails she can wear it on a chain around her neck until it's resized. Maybe you should carry a chain in your pocket when you propose, just in case?

As pointed out in one of the comments, completely surprising her with the whole idea of getting married (rather than just the circumstances of when you'll ask) is not necessarily as good an idea as our romantic-fiction-driven ideals would lead us to believe. Make sure you and she are on the same page about marriage, without necessarily making her certain whether/when you will propose.

Also, if her parents are at all present/important in her life, make the effort to get their blessing before you propose. Their refusal won't make anything worse than it would end up being anyway, whereas their blessing will make everything much happier for all.

Oh and one final note, having read one of the previous answers. If you surprise her a little, and you make it romantic, and you offer to devote the rest of your life to her, and while offering her a diamond ring to seal all of this you explain the very reasonable fact that you didn't know her ring size so it might be a little too big---if after all of that she looks at the size and scowls and says "oh, so you think I'm that fat??"---then, my friend, this is what you do: marry someone else.

  • 6
    "-if after all of that she looks at the size and scowls and says "oh, so you think I'm that fat??"---then, my friend, this is what you do: marry someone else." If only it were possible to +10. +1 will have to do
    – Pharap
    Commented Dec 20, 2015 at 15:35

Buy yourself a simple ring for some pretended reason. (Go to a fantasy store, buy it in a thrift shop, whatever seems reasonable for you to do).

The best scenario would be, if she is with you when you buy the ring, so you can take another smaller ring and jokingly say this one would fit you.

Otherwise find a chance to let her try it on. If it fits (which I doubt), perfect. Otherwise you have an idea on how much smaller the ring should be.


So yeah on the other day I went to visit one of my friends with my girlfriend and their cute little kid made a ring with play doh clay for my gf. That was the cutest thing bruh!

enter image description here

so what was the question again?


I did it with a bit longer plan, we were in town, eat out and so on, went to for shopping (this was just one normal day), then I got an idea suddenly, we went to jewelstore and just for fun "were looking ring to my self", then as a play asked her to try that and others also, after wards I asked that price (and size) from salesperson, then after few days went to look proper ring for her that size, of course got again help from salesperson.

I got new ring, girl and perfect ring for her :)

sorry my bad english


Get some plaster and a shallow rectangular box. Get her to make a hand print. It has to be a deep one - you want her to insert her hand into the plaster far enough that the plaster envelops the widest part of her ring finger (i.e. the joint).


This gives you the width of her ring finger. A totally nonscientific test on my own finger shows that width and height of the finger are similar, so this should get you pretty close.


Have you considered that if she doesn't wear rings, a ring might be a poor gift? Okay, if you're about to propose, then carry on. Get a ring that's too small (size 5 or 6 is a good guess) and the jeweler will generally resize it for free.

Always go too small -- avoids the whole "You think I'm fat!" series of difficulties.

  • 22
    I'd call this big fail if I set up that romantic moment and couldn't even squeeze the ring onto her finger. Who's going to feel "Man, I must be too fat" then? Commented Dec 17, 2015 at 15:26
  • 1
    Also, err on the small side because it's easier to enlarge a ring slightly (but putting it on a mandrel and hammering it down), but harder to shrink it. Commented Dec 17, 2015 at 20:00
  • 3
    What's easier for the jeweler isn't your concern. What's less destructive to the ring is, see Robert's "Ask" answer. The OP might as well ask her what size she is if the ring isn't going to fit at all. Ruin the moment now or later, or play it safe and go too big; ruining nothing except another afternoon at the jewelers.
    – Mazura
    Commented Dec 17, 2015 at 22:45
  • 8
    Plenty of people, myself included, become accustomed to wearing rings for the first time only once they get married. It's a very small but emblematic part of the way marriage changes your life. If she discovers she truly can't get used to the sensation, she can always wear it on a chain instead. And if she hits you with the you-think-I'm fat line while you're proposing to devote the rest of your life to her then the correct response is to take the ring back, give it to someone else and chalk it up as a lucky escape.
    – jez
    Commented Dec 19, 2015 at 19:42
  • 1
    @Mazura if you're paying for the changes, it definitely is your concern! Different metals have vastly different properties, and changing a silver or gold ring is easy compared to platinum (for example). The cost difference can be massive. Source: my girlfriend is a jeweller and had to change wedding rings that didn't fit.
    – ian
    Commented Dec 25, 2015 at 0:29

If it was for a random gift, I would get some toy rings for each of us, like Mood rings, and have fun. Both of us would have one, and it would be a goofy time. And then, I'd know how she adjusted it for her fingers.

If it was for an engagement ring... I wouldn't propose to anyone that I hadn't previously discussed marriage with, including the cost of the rings, the metal and design, and the size.


If you are ever going to a costume/fancy-dress party, you can get ostentatious costume rings with ridiculously large plastic gems in them. These are open rings that you bend the bands closer or further apart to make fit. If you can get her to wear one of these, you can know the size of her finger after she takes it off.

Not the answer you're looking for? Browse other questions tagged or ask your own question.