11 Things You Need to Know about Engagement Ring Sizing

Ring sizing has its own chapter in the book of advice on buying an engagement ring. So as part of your ring education, check out this definitive guide on how engagement ring sizing works. 

1. Understanding Ring Sizing By Numbers

Here in the US the ring sizes are based on a numerical scale. These numbers are based on the circumference of the inside of a band, expressed in millimeters. Sizes start at about a 3 (teensy) and go up to about a 15 (giant). The difference from one whole ring size to the next a matter of 2-3mm in the circumference of the inner part of the band, where it touches your finger. The difference between a comfortable ring size and one that either falls off or causes you to panic it’s so tight could be the matter of a 1mm difference in the inner ring circumference. You’ll see half sizes (size 5.5), quarter sizes (7.25) and even “loose” and “tight” sizes, which are basically like an ⅛ size increment. For example a “tight 6” is basically a 5 ⅞. The vast majority of people have a ring size somewhere between 4 and 12. For those of you abroad, we cover European ring sizing later in this post.

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2. Basic Ring Finger Knowledge

Engagement rings and wedding bands are generally worn on the left ring finger, which is usually smaller than the right ring finger, as most people are right-handed. If she’s left-handed, that finger will be a tad larger than her right hand’s ring finger. Why? Usually, the dominant hand’s ring finger is ½ a size larger than the non-dominant hand. This is important, as most women don’t know what their left hand ring finger size is but many know what their right hand ring finger size is. Catch our drift?

3. What is Her Ring Size?

The average woman’s ring finger is a size 6, for a ring that is about 2-3mm wide. When you go to a jewelry store, most women’s rings in the case are either 6 or 6.5, and the bands are all about 2-3mm wide with a few exceptions. The vast majority of engagement rings will be in the range of 5.5 - 6.5. Of course it’s not uncommon to be smaller than a 5.5 or larger than a 6.5, but almost all engagement ring orders in the US fall in this tight range. These size differences vary by very small amounts. For example, the difference between a 5.75 and 6 ring size is so so so so slight. Just eating too much salted popcorn can cause your fingers to swell more than a 1/4 size the next day. So don't get stuck in the weeds on sizing. If you know she's somewhere between a 4 and a 4.5, stay with the larger end and you'll be ok. Making adjustments after the fact is totally normal. 
That said, if a ring were a basic t-shirt: 
Small hands: 4.5-5.5
Medium hands: 5.75-6.5
Large hands: 6.75-7.5

4. Consider the Width of the Ring ​

The wider the ring (or rings), the tighter it will fit on a finger. PAY ATTENTION, there will be a test.  If you love a ring that is on the wider side ( 5mm and up) consider going up about a ½ size for every millimeter past 4mm. Keep in mind that adding a wedding band to stack next to an engagement ring will increase the width.

5. Strategies for Figuring Out Her Ring Size

Ok, it’s time to get your MacGyver on. Somehow you misplaced that piece of paper with your girlfriend’s professionally measured perfect ring size. DAMMIT. Don’t worry, we have ways:
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Ring Size Measurement Methods that DO work:

• Send us a picture of your girlfriend where we can see her hands - we’ll be able to give you a pretty solid size based on a picture. Sounds weird? It is. We are weirdly good at this. (See image to the left, likely a size 5.5)

• Pick a ring that she can resize, and let the jeweler know that you’ll likely need to do that.
• Ask her close friend or family member.
• Try swiping a ring that fits her and pressing it down over a tapered candle. Then bring that to a local jeweler and try to match it to one of their official “ring sizing bands” or measure the circumference of the indent in millimeters and use this chart
  
  

​Ring Size Measurement Methods that DON’T work:

• Don’t try to tie a string or wrap a piece of paper around her finger in her sleep. Just don’t. This is a futile mission. Ring sizes vary by such small degrees that you’re just not going to get it right.
• If she’s in on the secret then don’t use a free plastic ring sizer or a free ring size guide that you printed out online. They can be misleading. Have her go into a store and be professionally sized using a metal ring sizing set.
• Don’t use the same ring size you got from the giant cocktail ring she wears on her middle finger.

​6. How to Pick a Ring Size for an Eternity Ring 

,,Eternity rings feature diamond accents that go all the way around the band of the ring. If you’ve got your eye on a sassy channel set diamond eternity ring style keep in mind that these rings cannot be resized. Don’t order one unless you know her size for sure, or you have a jeweler who will guarantee to remake the ring for you in the correct size if you need to. If she's between sizes, go with the bigger size. ​​

7. How Does a Jeweler Resize a Ring?

Resizing a ring means that a tiny little surgery needs to occur on the part of the ring under the finger. They will heat it up, split the band at the back, and either add a bit of metal to increase the ring size or subtract a little bit to decrease the ring size. Resizing can be more complicated, but this pretty much covers the basic procedure.

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8. Read the Fine Print

MAKE SURE that you have a ring sizing policy and/or a return or exchange policy in writing. Larger jewelers offer ring resizing policies that include eternity rings. To you it’s a resize, to them it’s an exchange because they need to make a new one. Here’s an analogy: if you buy a fancy Al Capone hat that doesn't fit, sometimes they can stretch it to fit you and other times you need to straight up exchange that piece of flair for a bigger one that will fit your noggin. All those brains you’ve got up there… use them to figure out whether or not your have a solid ring sizing and exchange/return policy in writing.  ***Side note: custom designed rings often don’t come with an exchange or return policy, but a simple free resize within 1 size up or down should always be offered. ​

9. How to Plan for Ring Sizing in your Future

It’s a long a winding road and there are many situations in a person's life that may call for a size adjustment - usually up. Adding a wedding band to the situation increases width, and what do we know about increased width…? Increased with makes rings fit tighter. Maybe your engagement ring hurts going over the knuckle, ouch. And let’s face it, we aren’t getting any smaller as we age. Tissues and joints tend to expand over time and during pregnancies - fun times. How many times in a ring’s life can it be resized? Usually you can resize a ring twice in it’s lifetime. Sometimes more depending on how simple the band is. If there are no gemstone accents, you have a lot more leeway in terms of future resizes. If the band of your engagement ring is spangled in gems, resizes should be limited or avoided in some cases. There is strategy upon strategy with how to deal with this and sometimes things like sizing beads, sizing bars and euro shanks come into the picture. Don’t go cross-eyed, just drop us a line if you have questions about this. We will hook you up with answers. ​

10. European Ring Sizing 

Yep, this question comes up for a number of reasons:

1. We have clients all over the world. Hey Dubai!
2. Maybe you are hunting down a super specific designer in another country or you’ve found an antique ring so one of a kind that you simply must ship it from Amsterdam to Wisconsin. Cool. I hear you. I’ve almost done it myself.  
3. Or maybe, just maybe you’re in London and just really feeling yourself and you thought you knew her ring size was a 6, but how do you convert that over?

You can easily Google it or you can use this handy European ring sizing conversion chart. Note, the average UK ring size for a woman is M ½ (6.5)

11. Men’s Wedding Ring Size Pro Tips

The average ring size for men is 8, and that’s for a ring that is about 4-6mm wide. When you go to a jewelry store, most men's rings in the case range from a size 8 to a 9. Men tend to wear just a single wedding band. There are MANY different styles, and NO you don’t have to match your ring to your partner’s. Wear what you want boys! Check out some of our favorite men’s wedding bands.

Little Bird is all about offering engagement ring buying tips. The best way to buy an engagement ring is with our help, so feel free to drop us a line and we will be happy to spend some time on ring size advice.