How to Find Out Her Ring Size Without Her Knowing?

Written by: Benjamin Khordipour, Jewelry and Gemology Expert
March 19, 2020 – Posted in: Jewelry Blog

Imagine this, you get down on one knee and pop the question. As you slip the ring onto your partner’s finger, both of you suddenly realize it doesn’t fit. You rushed things and didn’t take the time to find out her ring size, and the moment is spoiled.

Okay, it might be possible to resize the ring and make it fit. But there’s no reason to kill the romance if you prepare for the occasion. This write-up provides tips and tricks to determine your partner’s ring size without raising suspicion.

  1. Borrow One of the Rings She Wears
  2. Trace a Ring She Really Likes
  3. Estimate based on the Hand Size
  4. Get Her Finger Size While She’s Sleeping
  5. (Our Favorite Tip) Get a Cheap Ring Sizer
  6. The Good Old Comparison Method
  7. Ask Her to Try on a Dummy Ring
  8. Employ Others to Help You
  9. Take Advantage of a Shopping Day
  10. Ask for Her Ring Size Directly

Women’s Ring Sizes 101 – General Tips

Artistic Aquamarine and Diamond Ring on Finger

Keep in mind that ring measurements are quite precise. For women, the sizes range from 3 to 10, or 14.1 mm to 19.4 mm in circumference. The key thing is that the numbers indicate the inside diameter of a ring.

In general, the most common sizes in the US are between 5 and 7, and size 6 is the most popular. In millimeters, this translates to 15.7 mm (size 5), 16.5 mm (size 6), and 17.3 mm (size 7). Your future spouse’s finger might fit between two sizes and, of course, there are sizes 5.5, 6.5, and so on.

Regardless of the actual measurements, the idea is that the ring fits comfortably. It should be snug to stay on the finger. But the ring should also be a bit loose, so there’s no resistance when your significant other wants to slide it off.

With this in mind, two different ring sizes might fit your future spouse. In that case, it’s advisable to go for the larger size. Sometimes, the knuckle might be larger than the finger. If so, choose a ring that’s half a size bigger to ensure it can be taken off easily.

When you measure the size, it’s important not to use any kind of flexible string because it may stretch and give you the wrong result. And if you decide to opt for a ring with a large band, you should go half a size up for more comfort.

Finally, the measurements presented in this section are standard in the US and Canada. Should you decide to get the ring from abroad, you need to check that country’s sizing standard. Then, the International Ring Size Chart can help you convert the size to US standards.

10 Tricks to Determine Your Beloved’s Ring Size

Now you know the ring sizing basics, it’s time to start the detective work. The following tips are straightforward, but you should be careful to remain stealthy at all times and keep the poker face on.

Borrow One of the Rings She Wears

Personal Ring Collection

This is probably the simplest strategy, but there are certain challenges. First, you need to be 100% certain that she wears that particular ring. Otherwise, you might be snatching a piece that no longer fits.

Then, it’s important to make sure she doesn’t figure out the ring is missing. Therefore, it’s better to go for pieces that aren’t that valuable or hold great emotional value.

Once the ring is in your hands, you have two options. Measure the ring’s inner diameter on the spot and figure out the corresponding size on your own. Or, you can rush the ring off to the nearest jeweler and have the professionals determine the size.

The latter option might be better because you’ll surely get the right size and some extra tips on how to choose a perfect engagement ring. On a side note, consider borrowing a ring she likes.

This helps you kill two birds with one stone. You’ll get to determine the size and the engagement ring style she favors.

Trace a Ring She Really Likes

Drawing Size of Finger for Engagement Ring

Sometimes borrowing a ring isn’t an option. But there’s no reason to despair, you can always trace the ring on a piece of paper and use that to get the right size.

Again, you’re tracing the inner circumference of the ring. However, you might want to take the tracing to a jeweler, rather than try to guess the size on your own. And you should choose a wedding-band-like ring that can lay flat on the paper.

Rings that have a large crown or a lot of embellishments at the top are hard to trace. If you miss the measurement by just a millimeter or two, you might be getting a ring that’s a size bigger or smaller. That being said, a ring that’s slightly larger isn’t usually a problem. But if it’s smaller, she won’t be able to slip it on.

Estimate based on the Hand Size

Woman wearing engagement ring

Jewelers have become really good at determining the correct ring size based on different tracings. This time, you won’t be tracing the ring, but your beloved’s entire hand. And there are a few things to consider if you’re to do it the right way.

To begin with, engagement rings are usually worn on the left hand. That is, the ring finger of that hand. So, you need to come up with a clever tactic and persuade your partner to buy the trick, without raising suspicion.

Make it kind of a game and say you need the traces for an artsy project. And why not let her trace out your hands to make the game appear more convincing. All the while, make sure that the trace is as precise as possible and try to outline her fingers without any wobble.

Then, you can take the tracing of her left hand to the jeweler to estimate the size. There is an option to guestimate the size from the tracing on your own. However, it’s tricky and not worth your effort.

Get Her Finger Size While She’s Sleeping

Measuring Ring while she sleeping

This is by far the trickiest strategy because there’s always the risk of her waking up. But if you have steady hands and she sleeps like a top, feel free to give it a try. Should she wake up, you can play the fool and say you were just admiring her long slender fingers.

Anyway, the catch here is to use a soft tape measure like tailors use. To reiterate, pieces of string might be more convenient, but they won’t give you the correct size. The same goes if you decide to use a narrow strip of paper.

That out of the way, gently wrap the tape measure around her ring finger and make sure it’s snug. Hold the loose end of the tape measure between your thumb and index finger, and atop her ring finger. This way you minimize the chances of getting the wrong measurement.

Get a Ring Sizer

Ring Sizer Picture for Blog

You can hardly go wrong if you get an inexpensive ring sizer, but this method is quite similar to the previous one. To explain, the ring sizer you should be getting is like a tape measure – usually, a soft plastic band with a noose.

Your job is to get the noose around her finger and tighten it, so it fits comfortably. Then, there’s an arrow that points to the correct ring size. Of course, the catch is to do this while she’s blissfully unaware of what’s going on.

How to Use the Ring Sizer to Measure your Finger Size?

Nevertheless, this method is trickier than the previous because you’d need to loosen the ring sizer before you take it off. If you do it while she’s asleep it’s like playing the buzz wire game. One wrong move and say goodbye to your surprise proposal.

On the upside, this method is among the most accurate. And you may set the sizer against one of her rings to estimate the size without risking the romance.

The Good Old Comparison Method

Engagement Ring on Finger

Although not exactly the most accurate, the comparison method is one of the safest. This is something couples often do and she isn’t likely to suspect anything.

So, take her left hand and place it on top of your right hand. Then, figure out which of your fingers is the same size as her ring finger. For example, your small finger might be the same or slightly bigger than her ring finger. Now, you measure your finger to estimate the correct ring size.

As this method isn’t precise, it would be best to take some extra steps. When you determine which of your fingers is the same as her ring finger, try to slip one of her rings onto that finger. And if you’re lucky, it’ll fit like a glove.

But then, it’s still advisable to consult with a jeweler and tell the professional how you got the size. Chances are, you might need to go half a size up or down to be certain the ring will fit.

Ask Her to Try on a Dummy Ring

Ring for Sizing

The dummy ring trick is fairly accurate, but it requires some witty persuasion tactics on your side. In other words, your beloved needs to think it’s a fun game and you’re just goofing around.

So, you should find a plastic toy ring and come up with a convincing story to explain how the ring got into your hands. A narrative that could work is that you got the piece from a claw crane machine and a voice in your head told you the ring was for her.

Don’t forget to maintain the happy-go-lucky tone and approach the trick with humor. Otherwise, she might figure out something else is at play and confront you with uncomfortable questions. But if all goes well and she puts the ring on, you’ll know her size.

And even if the toy ring turns out too big or too small, you can still get a pretty accurate estimate.

Employ Others to Help You

Girls helping for Ring Sizer

If you believe there’s no other way to get the right size, you can ask friends and family members for help. However, it’s best to avoid her friends and family members because it might be hard for them to resist the urge to tell your partner what’s going on.

Therefore, you should seek help from your friends or family members. Your future wife is surely close to one of your siblings or friends. And if the person plays it right, there’s no reason to worry about them spilling the beans.

What they can do is ask your partner to try on one of her rings. And if it fits, you now have a dummy finger to measure and get the correct size. There’s also an option to ask your partner about her ring size. But then, she might suspect something fishy is going on.

Either way, you need to be careful about two things. First, select the person whom you can entrust this sensitive task. Second, come up with an approach that won’t hint at your final goal.

Take Advantage of a Shopping Day

Shopping center

More often than not, jewelry shop display windows grab female attention. Why not ask your partner to go inside and check out the jewelry? And you don’t even need to focus on rings. As she browses through the display cabinets, find a ring you think she would like and ask for her opinion.

If she’s into the style she’ll be willing to try it on, and you’ll know exactly what’s her size. The great thing is that this method also allows you to kill two birds with one stone. You’ll figure out the right style and size at the same time.

Just try to keep things cool and casual. Should your future wife see you’re getting nervous and excited, she’ll know you’re up to something.

If your located near 5th in Manhattan, feel free to book an appointment and we can measure your finger in our showroom.

Ask for Her Ring Size Directly

Ring on Finger Hand

Yes, this method spoils the surprise and kind of defies the title of this write-up. But a lot of couples discuss marriage and engagement well before it’s time to propose.

Asking her about technical details like the ring style and size might be against the traditional engagement etiquette. But it won’t really diminish the romance when the moment to get down on one knee comes. There’s a lot of room to impress your lady and make the event memorable.

Size Matters

When all is said and done, figuring out the ring size sans the suspicion shouldn’t be that hard. And if one of the methods fail, there are plenty of other tricks to try out. But whatever you do, you shouldn’t purchase a ring before you know the right size.

Granted, it’s possible to resize it after the proposal. But do you really want to put your significant other through the hassle?