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How to Measure Ring Size for a Surprise Proposal

So, you have found the one and are finally ready to pop the question! When planning the perfect surprise engagement, you are not alone in wondering how to find your partner’s engagement ring size without them knowing. Luckily, we have spoken to our jewelry experts and uncovered all the different ways to subtly measure your partner’s ring size!  

Measure Your Ring Size with Our Free Ring Sizer Tape Measure  

We will happily send you a complimentary plastic ring sizer so you can easily find your perfect ring size at home.  

How to Measure Your Ring Size with Our Free Ring Size Conversion Chart  

  1. If you would like to measure your ring size with a piece of paper at home, print out our ring size conversion chart. Before you print the guide make sure the page scaling is set to “none” on your print dialog box.  
  2. Take the ring size chart and place your ring over the circle that aligns with the inside edge of your ring. Make sure you are using a ring that fits the same finger (and hand) as the ring you want to purchase.  

How to Measure Your Ring Size with Our Free Printable Guide  

  1. Alternatively, you can print our ring size guide at home to measure your ring size. Before you print the ring size guide make sure the page scaling is set to “none” on your print dialog box.
  2. Cut out the ring sizer and then cut a slot on the dotted line. Wrap the ring sizer tightly around the widest part of the intended finger with the numbers showing toward you. Insert the arrow-end through the slot you cut. Your ring size is the number that lines up with the slot.

How to Measure Ring Size Using String, Paper, and a Ruler  

6 Ways to Measure Ring Size Without Your Partner Knowing  

  1. Be Subtle 

If you are set on a surprise proposal but want to have the correct measurement by getting the information directly from the source, you must acquire the information in a very subtle way. For example, if you are proposing to your girlfriend, you can pretend you are going to buy a ring for your mom, sister, grandma, or even yourself. Just make sure this pretend recipient is someone whose finger is similar in size to your partner’s left ring finger. Casually ask what your partner’s ring size is for reference. If you really want to step up the ruse, purchase an inexpensive ring and have your partner try it on to see if it is the perfect fit. And afterward you can give that decoy ring to your mom, sister, or grandma to appease your guilty conscience!  

  1. Ask Friends 

One of the best ways to find out your partner’s ring size is to ask one of their friends. If the friend does not know right away, he or she can be the one to ask (nonchalantly). One step better, ask the friend to take your partner engagement ring shopping “for fun.” That way your partner will get professionally sized and maybe drop a hint about what styles they like!  

  1. Borrow a Ring

Another strategy is to borrow one of your partner’s rings for a day. You do need to be careful with this tactic because it might backfire. Make sure you borrow a ring that they won’t notice is missing and that’s similar in size to your partner’s left ring finger.  

  1. Leave a Trace 

If you are terrified of losing one of your partner’s rings, try this method instead. Take one of their rings and place it on a piece of paper. Draw a circle on the inside and outside of the ring. Do this several times to make sure your ring traces look consistent and can indicate the correct ring size. A Brilliant Earth Jewelry Specialist can typically figure out the measurement of the inner diameter from your sketch! Even better, use our ring size conversion chart for additional tracing accuracy! 

  1. Enlist an Engaged Friend 

If you and your partner are spending time together with someone who is engaged, secretly ask that engaged friend to let your partner try on their engagement ring. This will put you in a ballpark size range to start out with. You can also use this as an opportunity to ask your partner what they thought of the friend’s engagement ring (in private) to try to do a little sleuthing as to what style of ring your partner would like. 

  1. Compare Fingers 

This method is a little less accurate, but if you are desperate, go ahead and try it out! When you are holding your partner’s hand, see if their ring finger is similar in size to one of your fingers. For example, their left ring finger might be as big as your pinky. Again, this strategy will not be as accurate, but the more measurement information a professional jeweler has about your partner’s ring size the better!  

6 Ring Size Tips and Facts 

  1. Our dominant hand tends to be slightly bigger, so make sure you are measuring your partner’s left ring finger.
  2. If you haven’t gotten your partner’s exact measurement, err on the larger size so the ring is sure to slip over the knuckle of your partner’s ring finger when you propose.  
  3. The most common women’s ring size is 6 to 6.5. 
  4. The most common men’s ring size is 10. 
  5. Wider bands have a tighter fit than thinner bands, so if you borrow a ring to measure, try to make sure that it is the same width as the ring you plan on purchasing.
  6. Finger size changes a little throughout the day because of temperature, activities, etc. When warm, fingers tend to expand slightly. When cold, fingers tend to shrink. Most people find they have puffier fingers in the morning, but that their fingers shrink to their normal size during the day.  

Ring Sizing FAQs  

Do I measure my ring in mm or cm? 

In the United Stated and Canada, ring size is most commonly measured by the inner diameter of the ring in millimeters. At Brilliant Earth, we also measure in millimeters and convert the measurement to the nearest half ring size.  

What is a comfort fit and how do I measure for it? 

The shape of the ring’s inside edge is what determines if it is a comfort fit ring or a standard fit ring. Standard fit rings have a flat inside edge that fits snuggly against your finger. Comfort fit styles, like our Petite Comfort Fit Ring, have a beveled or curved inside edge that allows the ring to more easily slide on and off your finger. Comfort fit rings are ideal for those with wide knuckles or hands that easily swell.  

What if I order the wrong size ring? 

Brilliant Earth offers complimentary ring resizing within the first 60 days for most rings. This is to ensure customers get the perfect fit. We also offer complimentary 30 day returns. If for any reason you are not satisfied with your purchase, you can return it within 30 days for an exchange or full refund. 

What happens when my ring is resized?  

When a ring is resized, the jeweler will cut through the back of the band and either remove or add metal to change the size of the ring. If your ring needs to be resized by two or more sizes the best course of action is to return the ring and repurchase the right size. An extreme resize can compromise the structure of the ring.  

Can all rings be resized?  

While most ring types can be resized, eternity ring styles cannot be resized due to their design. If resizing is a possible concern, it is best to choose an engagement ring with a metal back, like a solitaire setting. You can also consult with a Brilliant Earth Jewelry Specialist to ensure that your ring setting is eligible for resizing.  

How do I measure ring size using a ring? 

You can find the measurement of a ring you already have by taking a ruler and measuring straight across the center from edge to edge. Using the ruler, document the diameter in millimeters. Take that number times 3.14 to find the circumference of your ring. Compare the circumference to our ring sizing chart to find your size. 

Can I measure my ring size at home? 

The best way to find your ring size at home is by ordering a free Brilliant Earth plastic ring sizer. If you need to find your ring size on the spot, the next most accurate approach is using the string and ruler method listed above.  

What if I can’t figure out the size?  

If you can’t figure out your partner’s ring size or don’t want to risk being wrong, consider a temporary setting to propose with. Brilliant Earth offers an 18K White Gold 2mm Comfort Fit Ring as a temporary setting. With this option you have 60 days to propose, have your partner sized, and return the ring. Once you have your partner’s perfect fit, Brilliant Earth will set your diamond in your chosen setting. This method allows your partner to see the diamond you chose, but there isn’t the risk of having to resize the actual setting. This method is also a great option for those who don’t know whether to purchase an engagement ring before or after proposing. Please live chat or contact us if you are considering this option.  

Final Thoughts  

Something to keep in mind is that the most accurate way to find the perfect ring fit is to have your partner’s ring finger sized by a professional jeweler. Using one or several of the methods above will result in a close approximation, but there is always the risk that your measurement will be slightly off. For custom engagement rings we highly recommend visiting a jeweler to get an accurate size because custom pieces are final sale and may not be able to be resized in the future. 

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Comments (74)

Ellen H Singel Says:
April 25th, 2019 at 8:47 am

My fiance took me to a ring store in the mall “spontaneously” and asked them to size me “for fun”, then he didn’t propose for another year and a half. Very tricky!

robin pittis Says:
March 26th, 2019 at 4:09 am


Lita Moore Says:
January 24th, 2019 at 7:20 pm

What can I do to help out

Eder R Estudillo Says:
August 17th, 2018 at 12:46 pm

The ring sizer is a great idea

Dayle Rounds Says:
August 14th, 2018 at 10:03 am

Thank you for your offer of the free ring sizer.

Jan Beckwith Says:
July 26th, 2018 at 4:36 pm

Would like to have one of your ring sizers.

Claudia Says:
July 23rd, 2018 at 6:23 pm

Love your rings please send me a ring sizer Thanks

Timmy Says:
June 14th, 2018 at 2:11 pm

Thanks for having me.

Angela Lang Says:
May 13th, 2018 at 9:47 pm

Requesting a free ring sizer. Please send asap.

Angela Lang Says:
May 13th, 2018 at 9:46 pm

Please send me a ring sizer asap

Tony Jilnicki Says:
May 5th, 2018 at 8:32 pm


Christopher Olivera Says:
March 24th, 2018 at 8:45 am

Requesting free Ring Sizer, thanks!!!

Joshua Says:
March 10th, 2018 at 3:07 pm

Thanks you very much

Joshua Says:
March 10th, 2018 at 3:07 pm


joel a Says:
March 6th, 2018 at 6:08 pm


vincent elwick Says:
February 27th, 2018 at 3:43 pm

can i have a ring sizer

jose taboada Says:
February 27th, 2018 at 12:19 pm

will propose on april 21 2018

B. Earth Says:
February 19th, 2018 at 11:16 am

Hi Zach, we offer one complimentary resizing for our standard ring styles with free shipping both ways within 60 days of shipment to our US, Canadian, UK, and Australian customers. Please note our eternity rings cannot be resized due to their design. Custom, modified, and engraved rings are subject to resize fees. You can find more information on our return and exchange policies here: Thanks for your interest!

Zach DeGuzman Says:
February 15th, 2018 at 11:23 am

What’s the return policy for wrong size rings?

AARON McCauley Says:
January 31st, 2018 at 8:08 pm

I’d like a ring finger sizer

Kane Millikan Says:
January 16th, 2018 at 9:40 pm

Thank you for ring sizer

Jeff Siebenthall Says:
December 27th, 2017 at 10:43 am


Robin Garcia Says:
December 4th, 2017 at 9:44 pm

Request ring sizer

B. Earth Says:
November 29th, 2017 at 11:15 am

Hi Timothy, please fill out the form on the top of this page by clicking “Request Ring Sizer”. If you are having trouble, please contact our jewelry specialists at 1.800.691.0952 or through the live chat on our site. Thanks for your interest!

B. Earth Says:
November 29th, 2017 at 11:15 am

Hi Chad, please fill out the form on the top of this page by clicking “Request Ring Sizer”. Thanks for your interest!

Timothy Says:
November 16th, 2017 at 7:18 am

How do I request a ring sizer? When I try to enter myself in, it doesn’t do anything.

CHAD M Says:
November 15th, 2017 at 7:51 pm

Can you send me a ring sizer

april torres Says:
November 10th, 2017 at 2:30 pm

thank you

B. Earth Says:
October 27th, 2017 at 11:14 am

Hi Shari, you can get a ring sizer sent to you by filling out the form at the top of this post. Just click “Request Ring Sizer”. Thanks for reaching out!

Andrew Says:
October 27th, 2017 at 6:36 am


Shari Bishop Says:
October 25th, 2017 at 11:20 am

Looking for a ring sizer please

Laurence La Roux Says:
October 19th, 2017 at 5:36 am

Just taking a look

B. Earth Says:
October 18th, 2017 at 11:57 am

Hi Robert, you can request a free ring sizer by filling out the form at the top of the blog post. Thanks for your interest!

robert s corry Says:
October 17th, 2017 at 11:03 am

please send free ring sizer

B. Earth Says:
October 12th, 2017 at 1:57 pm

Hi Andrew, the form on the blog works. If you have any questions on the status of your ring sizer delivery please reach out to [email protected] or call us at 18006910952. Thanks for your interest!

Andrew Says:
October 12th, 2017 at 6:53 am

Hope this is the actual button to submit my info for y’all to send out the ring sizer…

Tyren Jones Says:
October 7th, 2017 at 5:29 pm


Kenneth Huffman Says:
September 26th, 2017 at 4:36 pm

I think this is a cool thing been wondering how to check her ringo size without her knowing

Cody Says:
September 21st, 2017 at 4:13 pm


Wolf Weisz Says:
September 15th, 2017 at 1:36 pm


David Says:
August 24th, 2017 at 6:25 pm

Ring sizer please

Justin wilkett Says:
August 7th, 2017 at 7:20 am

Thank you

Darren Says:
July 24th, 2017 at 1:39 pm

Or, if your girl is into scented candles, tell her it’d be fun to get her one of the “candles with a ring in them” (FragrantEarth, etc.) and tell her you need her ring size to order it. It’s not quite as obvious a move as buying a ring all by itself, since it’s about the candle as much as the ring. Worked for me!

Erick espinoza Says:
May 26th, 2017 at 10:42 am

Trying to propose without anyone knowing or saying anything

Benedict Doorly Says:
April 2nd, 2017 at 6:40 pm

Totally believe this – its not always easy to
get points such as this across but you’ve done an admirable job to your readers

Dacia Elder Says:
March 10th, 2017 at 3:14 pm

I haven’t checked in here for some time since I thought it was getting
boring, but the lst few posts are great quality
so I guess I will addd yyou back to my everyday bloglist.
You deserve it friend 🙂

Stephen Celeste Says:
February 26th, 2017 at 2:34 am

And yeah, discuss rings early in the relationship, then file the info for later use, if possible. That way, you’ll also know the styles she likes and if she has certain expectations of size or doesn’t even care for diamonds, etc.

Stephen Celeste Says:
February 26th, 2017 at 2:30 am

Actually, the ring size/shoe size thing does typically hold true… Except it’s your size in MEN’S shoes! (Usually about two sizes smaller than your typical women’s shoe size). Also, bear in mind that “fashion” shoes, like similar clothing, tend to vary somewhat wildly in sizing, so it’s best to use a winter boot or athletic shoe for this purpose. Good luck!

Planned ring, surprise proposal Says:
February 16th, 2017 at 12:10 am

Nancy Drew is right. Let her pick the ring. She’s going to wear this on her hand ever day for the rest of her life.

You can still make the proposal a surprise, with or without the ring.

Or a “surprise” will ruin what should be a happy time.

Derek Fischer Says:
February 1st, 2017 at 12:36 am

Ihave r??d so many posts ?oncerning the blogger lovers but this paragraph is really a good p?ece of ?riting, keep it up.

Cassandra Says:
November 8th, 2016 at 2:27 pm

I’m dreaming. These rings are beautiful and would look perfect on my size 7.5 finger.

Mrs Sydlar Says:
August 26th, 2016 at 2:10 pm

Im sorry but I hate that everyone is dictating about others opinions. Whether or not its true. I know that my husband asked me on our third date. He asked, Baby, what kind of rings do you like? I answered. When I was in Walmart with him I tried on some of their rings and that’s when he got my ring size. All that youran has to do is be a spy, really. He’ll surprise with your ring. Mine wasn’t expensive. I know that a woman on here said she hated her ring. If its a 3,000$ ring I wouldn’t hate it. Mine was really cheap. I’m sorry but it shouldn’t matter how much it is. What should matter was that he became brave enough to ask you for your hand. My husband for the longest time has put himself down for buying me a cheap ring. I have told him that I love him and that’s all.

Tony Says:
August 23rd, 2016 at 8:49 pm

I came here hoping to leave with some insight. The first two suggestions are really awful ?

Pamela Says:
July 10th, 2016 at 8:22 am

Why not offer to buy her a small promise ring of greater things to come. I know I LOVED my promise ring when I got it, but if she is eager, she will give you the facts you need!

Emily Says:
June 12th, 2016 at 4:50 pm

I work in jewelry and I can tell you that women’s shoe sizes have NOTHING to do with ring sizes.
Myself as an example wear a 5.75 ring and a 9.5 shoe. If I tried to wear a 9.5 ring on my ring finger it would fall off

Nobody Girl Says:
June 12th, 2016 at 4:24 pm

The shoe vs ring is NOT TRUE… I wear a size 8 shoe and a 6 ring. No.

Emsgirl Says:
March 29th, 2016 at 6:14 am

NancyDrew you could have sold it if you really wanted. You should be grateful you even got a ring and that someone would marry you!! Some of us aren’t that lucky!!

Nancy Drew Says:
March 8th, 2016 at 9:47 am

Please let her pick her own ring. My ring was so awful. The store wouldn’t take it back and the owner showed me 3 even worse ones. The 3,000 ring stayed in a drawer for 15 years until the cleaning lady stole it. It should be a Class A Felony to allow an unescorted man into a jewelry store!

Nancy Drew Says:
March 8th, 2016 at 9:39 am

Please let her pick her own ring! I got an awful ring. The store wouldn’t take it back. A $3,000 ring spent 15 years in a drawer until it was pilfered by a cleaning lady!

B. Earth Says:
February 16th, 2016 at 3:07 pm

Hi John,

If you are far away from her, you could ask one of her friends or family members for her ring size. If none of them know it, you could also enlist a friend or family member back home to try on one of her rings to compare ring sizes. Good luck! Our jewelry specialists would love to help you with any further questions and can be reached by calling 800.691.0952.

Johnbate Says:
February 15th, 2016 at 8:54 pm

I am currently working in a differnt country.
My questions are:
1. Does it make sense if I send the ring despite we’re faraway to each other?
2. Which other way can I know her ring size apart from the listed ones above?

Joel Says:
December 9th, 2015 at 10:40 pm

Who cares !

Diane Says:
November 16th, 2015 at 11:08 am

And now for the best answer…..her ring size is the same as her shoe size……(minus the narrow or wide). I know this sounds strange, but to my knowledge, this has always held true. So when she isn’t looking, check out one of her shoes…????

Patrick Says:
September 3rd, 2015 at 8:42 am

Hans…. sounds like you might have lost in love….. whether or not that’s true, don’t be so negative to the rest of us because of your experience….

Hans Says:
June 30th, 2015 at 10:15 am

I have a suggestion for all of you. How about you’ll all stop throwing your life away like that. Marriage these days is nothing but a business proposition – one that has the guy on the losing end of it. Are you really willing to do that? And then feel guilty for figuring out her ring size when you’re about to blow $50k on some carbon-based blingy stone?

Gavin Says:
June 28th, 2015 at 8:11 pm

My girlfreind is kind of a tomboy. She rarely ever wears jewelery other than the necklace i got her e while ago. Plus i don’t know what she’ll like. If she had a sister i would go to her, but her mom has about the same size hands… lol just because i posted this i now know what to do!

asIF Says:
June 8th, 2015 at 10:36 pm

I read somewhere else that you can take a ring you know fits her and press it into a bar of soap. Take the soap to a jeweler.

Ruben Fernandez Says:
May 19th, 2015 at 9:29 am

I would like a free ring sizer please.
Send to:
Ruben Fernandez
6624 El Parque Dr.
El Paso, TX. 79912

David Says:
April 25th, 2015 at 8:45 pm

Find a pic (or take one in secret – perhaps while she’s sleeping) of her hand next to an object that can easily be measured. Then, in photoshop or some other image edit application, find the ratio between the object diameter and her finger diameter and multiply that by the diameter of the object. Once you know the diameter it’s just a simple calculation to get the circumference (pi x D). Obviously, for best results get as close as possible and use the best camera you can find.

Bebe Says:
December 31st, 2014 at 2:33 pm

There is one way not listed here…. Try on one of her rings. Make a mental note of where it stops on your finger. Go to a jeweler and try on sizer rings until one hits the same spot on your finger. There you go.

Emily Says:
December 20th, 2014 at 9:45 pm

Why not just have one of her friends say something like hey can I borrow that ring its so pretty and being a good friend shed say yea but just give it back and BOOM you have a ring size

Scarlet Says:
October 8th, 2014 at 12:37 pm

How about… I dunno, taking a ring she wears a lot and trace it on a piece of paper. (Inside of the circle and out)

cluelussdumbgirl Says:
July 6th, 2014 at 11:40 am

How many of your friends know your ring size? Even better, ask the friend to take your girlfriend engagement ring shopping, REALLY? If one of your partner’s friends is engaged, ask her friend to let your girlfriend try on the ring? These are options for someone trying to buy a ring as a surprise? I have another one for you. Take your girlfriend to a wedding dress store and have her try one on, you know “for fun”. Then rent a white limo and drive her to a big church and have her walk down the isle, again just “for fun”. You see where this is going? Surprise…………………….

taylor1277 Says:
August 13th, 2013 at 10:16 pm

and did you know that the one thing that has measurements of the same between men and woman are ring szs.all you have to do too is measure your finger too and ask her to try on your will give you a ballpark figure also.