Wondering how to find out your girlfriend’s ring size for a surprise proposal? We’re sharing six sneaky ways to get the intel!

how to find out your girlfriend's ring size

So you’ve figured out what kind of ring she wants, you’ve done your homework on the four C’s, and you’re ready to pick out the perfect diamond.

But…there’s only one problem! You have no idea what size ring your future fiance wears. Believe it or not, this is a pretty common problem for guys that are shopping for engagement rings. How do you find out what size ring she needs without giving away your element of surprise before you propose?

Over the years, we’ve seen a lot of creative strategies. Today we’re going to share the ones that work time and time again for figuring out her ring size!

How to Find Out Your Girlfriend’s Ring Size

1. Find an old ring

Find a ring and trace it on a piece of paper or press it into a bar of soap to leave an impression.

Long before they get engaged, many women actually wear rings on their ring finger. If that’s the case for your future fiance, then you’re in luck.

Your jeweler will be able to use that to get an accurate ring size. If she didn’t wear a ring on her ring finger, you can still find a ring she wore on another finger and get a good estimate.

If you are really brave, go ahead and grab one of her old rings and bring it in with you when you shop for your engagement ring as a reference.

2. Ask in casual conversation long before you propose

If you know you are going to propose several months out, try to bring up her ring size in casual conversation.

This may be the most effective strategy, even if it seems the most dangerous! When she asks why, tell her that you were just wondering. She may think it’s a little strange at the time and get suspicious, but chances are that if several months go by she’ll have no recollection of the conversation.

Another great strategy to try is to wait and ask for her finger size around Christmas or her birthday. Then, buy her a cheaper silver ring as a gift to throw her off the scent!

3. Check while she’s asleep

Once you’re sure she’s completely out, take a thin piece of string or paper and slip it around her ring finger to measure.

This works best if she’s a heavy sleeper.  Be sure to wait until you can actually get to her left hand! If her right hand is what she uses to write, it could be up to a half size bigger than her left.

4. Ask her friends for help

Her friends will either have a decent idea of what size ring she might wear or could help you find out.

You could even come up with a plan that involves her friend asking, but it needs to be well thought out and not seem too random.

5. Ask her mother

This seems straightforward, but asking the parent can be tricky.

You’d be surprised to find out that many mothers have their daughter’s ring size memorized, or can at least give you a good idea by comparing to their own hands. Just make sure you evaluate the situation first!

If you’re worried that her mom might spill the beans on the engagement, you may want to choose a different strategy.

6. Guess big

If all else fails, it’s always easier to buy a ring that’s too big and have it resized. 

If you can’t find the opportunity to try any of the strategies above, you’ll still be fine if you just make your best guess on her ring size. She’ll still say yes to the ring that you give her, and will understand if you weren’t able to 100% nail the ring size. Resizing a ring up or down is a common process, and can be done very quickly in most cases.


Are you interested in creating your engagement ring with a loose diamond from our inventory this holiday season? Contact Sergio@jfjco.com to schedule an appointment and find the perfect diamond today.

Want to see some examples of our work? Take a look at our engagement ring photo gallery and video gallery. You can keep up with Jonathan’s on Facebook, Twitter, and even follow our personal Instagram accounts below:

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