How can I measure my ring size? - Sizer Reviews

This is the second of three posts that will focus on ring sizes. In this post I will review four different sizers available from Amazon. I have not been paid to review these products.

The first post detailed important factors to keep in mind when measuring your ring size, and the third will go through the methods jewelers use to size rings.

Good to Know Info

Before I get to the reviews I want to advise on how a ring should feel when it is the correct size. This is subjective but there are some guidelines* it is recommended you follow.

*All of these guidelines have exceptions so don’t worry if you encounter issues. Your local jeweler should be able to advise you if at-home sizing doesn’t pan out.

The first and most important is that the ring should not be able to slide easily over your knuckle when taking the ring off. Your knuckle is going to be your safety stop and therefore if you can slide your ring on and off with no resistance the ring is too big and will be easily lost. If you try to pull the ring off, with no additional movement, it should almost feel like your knuckle will separate first. Two or three “wiggles” should be necessary to get the ring back over your knuckle.

Conversely, the ring should go over your knuckle easily when you’re putting the ring on. If you meet resistance when putting a ring on do not force it on. You will have a difficult time getting it back off. A tiny bit of resistance is fine, like if the ring slows slightly but continues with no additional effort, but if it requires an increase in effort to get it on over the knuckle stop and try a bigger size.

What if the ring spins? Spinning is not always an indicator that your ring is too big. Most rings will spin to some degree. Some rings will spin, even if they fit perfectly, due to being “top heavy”. This most often happens with rings that have a large centre stone or tall setting. There are ways to offset this which I will go over in the third post.

Ideally your ring should feel like underwear: unnoticeable unless you’re consciously thinking about it! If you’ve never worn a ring before it can take a little getting use to, but you’ll get there in no time.


Reviews of Amazon Sizers:

I bought four different sizers from Amazon, all with decent 4+ stars reviews, with prices ranging from $3.99 to $6.99(USD). I’ll review them starting from the simplest.

*I’m not being sponsored or paid by any of the companies. Mainly I’m just curious how these sizers match up to ones I’ve used professionally.

I’ll be comparing them to my personal sizing tool(a mandrel) and my wedding and anniversary bands which are pictured below. Jewelers usually read sizes based on the “leading edge”, marked with a white arrow in the pictures, and each line on the mandrel represents a quarter size. You can see that my rings have a quarter size difference between them, with the ring with the wider band being the larger of the two. My wedding ring, wider gold band, is a 7.5, and my anniversary band is 7.25. Both are comfortable alone or worn together.



KIWEN Ring Sizer Measuring Set 1-17(US sizes) - $3.99


This sizer is similar to a zip tie with sizes marked in full and half sizes. It’s approximately 5mm wide, which is 2 to 3mm wider than most women’s wedding bands, but close to most men’s bands.

The marked sizes are legible but a little tightly spaced which makes the half sizes a bit harder to discern.

Initially when I tried it on, I overtightened it, and it read as a 6. This felt comfortable on my finger but there was no way I was getting it off over my knuckle. I loosened it gradually until I could wiggle it off, which got me to a size 7. The 7 felt very loose while at rest on my finger, and I could definitely see that causing people to want to opt for a smaller size, but remember I’m at minimum a size 7.25 on this finger.

In my opinion this sizer is decent. It holds its place well while trying to take it off and doesn’t slip to a larger size, but, overall, the sizes run small. Once you have it to the “wiggle off over your knuckle” stage I would add at least a quarter of a size to that measurement. Possibly even a half size. It’s easier, and usually cheaper, to size down rather than up.

Rating: 3/5

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REIDEA Ring Sizer with Magnified Glass 1-17(US sizes) - $3.99

This sizer is almost the same as the last but includes a magnified window, to help read the sizes, and an instruction leaflet. The width is the same as the one above, 5mm, so similar considerations should be taken.

The sizes are marked in full and half increments as well, with the numbers being neat and easy to read. Even more so with the magnifying window.

I followed the same method, overtightening first and loosening until I could wiggle it over my knuckle. This got me to a 7.5, which I think is pretty accurate. Again it felt loose at rest, but I think that’s just going to be par for the course with sizers like this.

I think this one is more accurate than the previous but it doesn’t hold it’s place as securely as the KIWEN sizer and would slip to a larger size when I was taking it off, unless I was careful. The accompanying instructions were concise and well thought, and written, out.

I would recommend the REIDEA sizer over the KIWEN, but only by a hair.

Rating: 3.5/5

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Mudder Stainless Steel Ring Gauges 1-13(US sizes) - $6.99


This is the type of sizers you’ll find in most jewelers. Each ring is either a full or half size, with half sizes being denoted by a “–“ before the number, eg -7 is 7.5.

What is different about this particular set of sizers, compared to those found in a jewelers, is that the interior is a mild Comfort Fit. This will affect how the rings feel, allowing them to be taken on an off more easily than a ring with a Flat interior.

The rings are approximately 2mm wide, which is the standard with for a women’s band.

I was able to comfortably fit on, and take off, a size 6.5, 7, and 7.5 with no issues. However, when I measured each sizing ring on my mandrel each size was smaller than stated by an eighth of a size.

While this may not seem like much, it can be the difference between an uncomfortably tight ring in the summer or a worryingly loose ring in the winter.

I don’t think I would recommend this sizer, but if you do have it, make sure you try at least 3 to 4 different sizes and go with the size that is too big to wiggle off but still offers slight resistance when removing it.

Rating: 2/5

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ACCMOR Ring Size Measuring Tool with Plastic Mandrel and Ring Sizer Gauge - $5.99

This sizer set is a combination of the last three. It includes two of the zip-tie style sizers, a set of plastic rings in full and half sizes, AND a plastic mandrel.

I was pleasantly surprised to find the plastic mandrel reads the same as my own.

Not only that, but it has two indented strips on either side with US and international ring sizes.

The strips being indented is also a nice touch as it makes this particular mandrel a "split mandrel". Split mandrels are used when the bottom point(culet) of a faceted stone extends into the "O" of the band. A regular mandrel, with no indent, would break the culet off of the stone in the ring you're measuring. This mandrel makes it safe to measure such rings. 

The zip-tie style sizers are approx. 5mm wide and clearly legible, with full and half sizes marked. They function the same as the either of the other two zip-tie style sizers, and hold their place when being maneuvered over my knuckle. I’m not sure why two were provided as I can’t see a discernable difference between them.

The plastic ring gauges are approx. 2mm wide and their interior is much closer to a Flat fit, than a Comfort, which means they should give accurate measurements.

I couldn’t comfortably fit on a 6.5, but a 7 and 7.5 felt right. Each of those sizes measured the correct size on both my mandrel and the provided plastic one.

I’m impressed with this entire set and I wouldn’t have any issue recommending it. The manufacturer does have a metal version for $8.99 if you prefer, but I haven’t tried that one to be able to recommend it.

Rating: 5/5

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Final Thoughts

I wasn't expecting much when I bought these sizing sets, but I was pleasantly surprised by most of them. The ACCMOR set is really the star of the group and I will be recommending that to customers and friends alike!

*Again, none of these reviews are sponsored and the reviews are just an informed opinion. 

The third post will be out next week, and will go through some of the methods jewelers use to size rings, as well as touch on some of the issues that might cause some rings to be trickier than others to size. 


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