How to Figure Out Your Knuckle to Finger Differential for Rings
Do you have rings that spin? Rings that Flop? Rings that jab you because they aren't in the right position?
Do you tend not to wear those rings much? What if it's your wedding ring? What?!? You're not wearing your wedding ring?
This is For the Girls With the Big Knuckles
As a large knuckle and spinning ring problem solving jeweler, I decided to share in this blog some of the advice I've shared with my clients.
The first step is to get your Knuckle to Finger Differential measured. I'll cover that in a couple minutes. There is a video at the end of the post showing how to determine your knuckle to finger differential yourself.
Since the style of your ring can contribute to a spinning ring, I'll address that first.
Some Rings Were Just Born to Spin

This Ring was Born to Spin. That's Why We Put in a Butterfly Spring.
Joan couldn't wear this ring comfortably to save her life. And yet none of her other rings needed help to sit properly on her fingers.
Joan was not a candidate for spinning ring solutions on any of her other rings. Just this one ring. And yet she loved it. So we put a butterfly spring onto it to stabilize it on her hand. Now she wears it in comfort and gets the compliments, because a stand up big gem ring is quite an eye catcher!
Some rings by their top heavy design tend to flop around. Their design demands that you do something beyond sizing it smaller (which won't handle the problem anyway) to get it to fly right.
The Three Possible Solutions for Taming Spinning Rings

Speed Bumps Can Help Arrest the Spin of Your Ring if Your Knuckle to Finger Differential is Not too Great
There are three basic possible solutions to spinning, flopping rings. They are covered in my, "Big Knuckles, Spinning Ring Solutions" Series:
1. Ring Spin or Ring Flop…One Possible Solution – Speed Bumps
2. Big Knuckles and Spinning Rings? Try the Butterfly Spring!
3. Finger Mate Hinging Shank for Rings for Enlarged Knuckles
What Determines if I need Speed Bumps, a Butterfly Spring or a Hinging Shank?

A Flexible Inner Spring, the Butterfly Spring, Helps Hold a Ring Upright for Those With a Larger Knuckle to Finger Differential
The first thing you need to know is your knuckle to finger differential. It is the difference in finger size between your knuckle and the finger area between your knuckle and the palm of your hand. Or as I call it, the area behind your knuckle. The bigger the differential, the more active a solution you need. The numbers of the solutions are in order of effectiveness.

This Client Has a Three Size Knuckle to Finger Differential as Figured Out With my FingerMate Flexible Sizer
The #1 Speed Bumps, help a bit, and sometimes that's all you need.
The #2 Butterfly Spring, helps more than speed bumps, but isn't as awesomely hardcore a solution as the hinging ring shank is.
The #3 Hinging Shank helps a ton, but it could be overkill if you don't have that much of a knuckle to finger differential. It also costs a lot more!
Another factor is the design of your ring. If your ring is very top heavy then you may need a more heavy duty solution on that ring than if you have an lower-to-the-hand design.
How is Your Knuckle to Finger Differential Measured?

This Multi-Sizer is Flexible and Allows You to Measure for Yourself When at a Distance From Your Jeweler
I like to use a flexible finger measurer. The normal hard metal ring sizers (Pictures of metal ring sizers) can only measure your knuckle and not the area behind it.
When I visit a client in person, I use the FingerMate sizer, which allows the finger area behind the knuckle to be measured properly as well as your knuckle. It's the red handled sizer I'm using Four pictures up.
See below for my how-to video that shows how you can use the Multi-sizer which can be mailed to you to determine your knuckle to finger differential if you are at a distance from your jeweler.
Video of How to Figure Out Your Knuckle to Finger Differential
Your Big Knuckle, Spinning Ring Solutions, Jeweler,
Calla Gold
Big Knuckle Blog Round Up
Ring Spin or Ring Flop…One Possible Solution – Speed Bumps
Big Knuckles and Spinning Rings? Try the Butterfly Spring!
Solving Spinning Stacking Ring Problem with Speed Bumps
Finger Mate Hinging Shank for Rings for Enlarged Knuckles
Review of SuperFit Hinge Shanks
Thank you for the informative blog post! Did you invent the term knuckle to finger differential? Do other jewelers figure this out for people? Lately I have noticed that some of my rings spin a bit, but they are still tight going over the knuckle. I’d like to find out what my finger knuckle differential is. I’d also like to share this with my mother. She rarely wears rings these days and I suspect it is because they spin around on her. Which is too bad because she’s loved jewelry as long as I’ve been noticing.
Dear Patricia,
There are some jewelers who certainly do figure out the knuckle to finger differential. Specifically the makers of SuperFit hinging shanks and FingerMate hinging shanks. And the jewelers who install these wonderful solutions on people’s rings.
I did come up with the phrase.
I hope to help you and your mom in the future.
Your Personal Jeweler,
Calla
Knuckle to finger differential! If only algebra problems had been this interesting. See, this is why it’s so important to have a personal jeweler.
Hello Amy,
So that’s why I’m a personal jeweler, because I so sucked at algebra? Seriously I learn way better with examples and stories too.
I like figuring things out and explaining things. This is a fun part of being a Personal Jeweler, blogging!
I’m glad you liked finding out how to figure out your knuckle to finger differential.
Your Personal Jeweler,
Calla
Ingenious describes these slippery, spinning ring solutions. I know so many people will want to take advantage of these techniques. I thank you for sharing the possibilities.
Thank you Judith! It seems that each time I deal with one of these spinning ring problems the response is so great. It means a lot to me to be able to take an many years unworn and spinning wedding ring and put a spring or hinge in it to make it wearable again.
Happy Solutions Jeweler,
Calla
Calla,
As someone with a fairly large differential of my own, I’m familiar with this problem! I spent a long time looking up solutions online for my ring. I actually never did see it explained as well as you did, though, in terms of which of the solutions that are best for smaller vs. larger differentials. Thanks for writing this post on it!
~ Shannon
Dear Shannon,
I’m so pleased that my explanation was helpful to you. The knuckle to finger differential is important to understand in order to figure out the best solution to spinning rings and other ring misbehaviors!
Your Personal Jeweler,
Calla
I take it this has to be done by a jeweller. Does this take long and is it an expensive procedure?
Dear Nettie,
This can be done in your home if you have the flexible sizer shipped to you. Or if your jeweler has a flexible ring finger measurer.
Figuring out your knuckle to finger differential isn’t the expensive part, the solution selected and the work done to make your ring comfortably wearable is the expensive part.
Each solution is priced based on how the ring itself is made and which solution is the best choice.
Your Personal Jeweler,
Calla
Dear Calla, Thanks again for another informative post. I have a question. In the post you number the solutions in the order of their effectiveness. I have copied them below: The #1 Speed Bumps, help a bit, and sometimes that’s all you need. The #2 Butterfly Spring, helps more than speed bumps, but isn’t as awesomely hardcore a solution as the hinging ring shank is. The #3 Hinging Shank helps a ton, but it could be overkill if you don’t have that much of a knuckle to finger differential. If you were going to include flat bottom shanks (Euro shanks)… Read more »
Hello Jelena,
That is an excellent question. I’d put square shanks with speed bumps. I often like to combine a square bottom shank with design elements that also help your ring not spin, like a low profile, wide shank and a horizontal orientation. When square shanks are combined with good design that increases their effectiveness.
Your Personal Jeweler,
Calla
Hi Calla,
Thanks so much for your reply.
Have a lovely day.
Jelena
I just got engaged. The knuckle on my “ring” finger is size 12. My ring size on the lower part of my finger in 7.7. Is there a solution for that large a differential?
Hello Alice,
That is an impressive “knuckle to finger differential.” I’d recommend a Superfit hinging shank which opens like a clam-shell. That way you can by-pass your large knuckle. Check out the pictures in this article:
https://www.callagold.com/all-about-rings/superfit-hinging-shanks-for-rings-review/
Let me know if you need further assistance as I do convert rings to Superfit hinging shanks.
Your Personal Jeweler,
Calla
Hello Cala this is all very interesting. I just had a very special favorite ring size enlarged to fit over my pinky knuckle and now the ring spins out of control. How much is the flexible ring sizer? And how much is the butterfly spring? And do I buy it from you and have my jeweler install it? Does it have to be sodered on? Would be great if this worked. Thank you
Gigi zeller
Hello Gigi, I understand how your ring is spinning. Once it’s large enough to go over the knuckle it’s now too big. Aggg. It’s a problem all right. I sell the flexible sizer. Just email me at callagold@gmail.com or call me at 805-963-4157 so we can get it to you and you can follow the directions on the video to figure out your own knuckle to finger differential. The butterfly spring is custom made to the width of your ring shank. Not all rings can take a butterfly spring successfully. The cost is determined by the width, how big around… Read more »