Beads are a big wide world that is interesting and super exciting to explore. But there’s so much to learn that you can easily get lost in it, especially if you’re new to beading.
Given the sheer number of materials, textures, shapes, and stunning colors and patterns beads come in, it might take you your entire beading journey to get it all.
While you can be certain about the shape and color of beads you want, getting the size right is usually somewhat confusing, even for more experienced beaders. Yet, it is the most vital piece of information for any beadwork’s success.
What is bead sizing? Bead sizing is the classification of beads according to their measurements. The universal standard is the length of the hole passing through it in millimeters (mm). However, seed beads go against the norm and have a whole different size guide.
Mastering these measurements can be pretty intimidating for a new beader looking to get creative quickly. It gets one thinking: How big is a 3mm, 10mm, or 20mm bead? Which bead size fits into what project?
If you are a newbie, then this is your lucky day because we will be answering these and more such questions in this guide. We focus on the key lesson of beading, and that is understanding bead sizes.
In here, you’ll learn all there is to know about how beads are sized, the suitability of each bead size for different projects as well as the stringing requirements. There are also helpful size comparison charts and invaluable tips. Let’s get beading!
How Beads Are Sized
Imagine the multitudes of beaders, bead stockists, and manufacturers spread across the world. What about the type of beads available? The average beader knows only about 7 types of beads, although there are like a dozen-plus more.
These numbers, borders, and bead diversity call for a standardized bead scale. That way, everyone is in harmony regardless of where they are making or buying beads from.
An easy way to measure the size of a bead is to purchase a bead sizer or bead size reference card. This sizer on Amazon is actually designed for measuring stone carat weight, but it would work well for beads too. I also love this reference card that can fit into a wallet!
Good quality beads tend to come with a matching price tag. You would not want to spend so much only to have them too small or too large for your needs – quite disheartening.
Standard bead sizing and a little knowledge enables beaders to find exactly what they are looking for easily. There are two primary bead sizes: the metric (millimeters) scale for standard beads, and the Aught size for seed beads.
1. Standard Bead Sizes (mm Scale)
Usually, the length in millimeters across the bead’s center hole, a.k.a. the diameter, determines the bead size. Swarovski beads, crystal beads, glass beads, gemstones, pearl, bone, wooden, and metallic beads use this metric scale.
Therefore, a 2mm bead size means that the hole passing through the bead measures 2mm in length. This length is also the diameter of the bead.
These sizes start at 2mm and can go up to 40mm and beyond. But the most commonly stocked size range for a lot of crafts is 2mm-20mm.
Now you must be wondering, What about multidimensional beads? Since all beads are not round in shape, and we have oval and even faceted beads, does the same methodology apply?
Well, yes. Regardless of the bead shape, regular or irregular, the hole’s length is the bead size. So a 2mm round bead, cube, oval bead, or multi-faceted beads are all considered 2mm beads.
However, some beads may have additional measurements indicated. For example, an oval bead will be size 7mm by 9mm, 7mm being the bead size (hole to hole length) and 9mm being the height.
2. Seed Bead Sizes (Aught size)
Seed beads have a completely different kind of scale from regular beads known as the aught size.
With this method, the size of seed beads is denoted by a number slash zero or with a degree symbol. A size 6 seed bead, for example, will be indicated as 6/0 or 6°.
What this means is, six beads placed in a linear arrangement is the equivalent of an inch. In other words, it takes six beads to string an inch of cord or beading wire.
Therefore, the bigger the number, the smaller the seed bead size because you need more to fill up an inch. Popularly stocked seed bead sizes are 15/0, 11/0, 8/0, 6/0, and 5/0.
They also come in an assortment of shapes and names depending on the brand. Some are rounded (rocailles), others are cylindrical, cubed, triangular, tubular (bugle beads), etc.
In the same light, seed bead sizes are not uniform across brands. It’s like every manufacturer has a distinct scale. If you happen to measure a 6/0 Miyuki, a 6/0 Toho, and 6/0 Matubo seed beads, the differences in dimensions between them will surprise you.
These variances, though subtle, add up to make a profound difference in the design outcome. Therefore, always stick to the recommended seed bead size and brand.
Choosing The Best Bead Size For A Project
Knowing the bead size is just one step towards finding the ideal beads for your project. You may have noticed that the bead size is in mm while most measurements for making jewelry and other bead crafts are given in inches.
Therefore, you must convert this millimeter sized bead into inches to determine the quantity of beads needed to complete a project.
We’ll explain this in more detail below.
Beads Per Inch
Here’s a bead per inch chart with bead sizes in mm against the number needed to string different lengths (16″ and 24″ are standard necklace sizes).
| Bead Size (mm) | Beads per inch | Beads per 16″ | Beads per 24″ |
| 2 | 12.5 | 200 | 300 |
| 3 | 8.3 | 133 | 200 |
| 4 | 6.25 | 100 | 150 |
| 5 | 5 | 80 | 120 |
| 6 | 4.2 | 66 | 99 |
| 7 | 3.6 | 57 | 86 |
| 8 | 3.13 | 50 | 75 |
| 19 | 2.5 | 40 | 60 |
| 12 | 2.1 | 33 | 50 |
Courtesy: International Gem Society
Now let’s look at the profile for each of these individual bead sizes, their hole size, uses, and stringing requirements.
Remember these dimensions especially bead hole sizes are not cast on stone and can vary widely by bead type. We are working with approximate numbers.
2mm beads
This is a tiny bead that measures 2mm across the middle and can be used in place of an 8/0 seed bead. It is about the same size as a new crayon tip or a nickel’s thickness, whichever is more familiar to you.
2mm beads have a hole diameter of 0.6mm-0.9mm. The ideal cord or beading cable size for it would be 0.8mm or 0.024”.
This bead size is perfect for creating intricate details and adding dimension to beaded projects. It is also a good size for bead embroidery, fringe earrings, and loom bracelets.
4mm beads
4mm beads are about the same size as the thickness of two nickels combined and can substitute 6/0 seed beads in patterns.
This bead size will have a hole of roughly between 0.8-1mm diameter, making a 0.024” or 0.6-0.8mm cord best suited for it.
Due to their small size, 4mm beads are loved for making lightweight, dainty and delicate jewelry pieces. They are also ideal for braided and clustered bead designs.
6mm beads
A 6mm bead is equal to the width of 4 pennies stacked up (each 1.52mm).
The hole size for this bead is likely to be between 0.8mm and 1.2mm. Any wire gauge between 21-23g or a 0.024” cord will be a good match.
6mm beads are perfect spacers for large-sized beads. They are suitable for non-bulky jewelry and other accessories.
8mm beads
If you stack up 4 nickels (each is 1.95mm in width), the stack’s height would be just about the same size as the 8mm bead.
Its hole size could be anything between 0.8mm-1.2mm. So a 21-24g wire and 0.024” beading cord works great with this bead size.
8mm is the most popular bead size for men’s bracelets and necklaces. It is ideal for countless other projects like dangle earrings, medium sized bracelets and necklaces, and as small chandelier beads.
10mm beads
The 10mm bead measures 10mm in diameter, which is the same size as a fresh green pea or the AAA cell diameter.
The hole size is about 1mm-1.2mm. A 0.024” cord will work this bead size effortlessly, and so will a 17-20g wire.
It is a versatile bead size for both men’s and women’s jewelry and is a favorite for making malas.
12mm beads
12-millimeter beads are about half an inch in diameter. That is the same as a half of the first joint of an adult’s index finger.
The average hole size is between 1-1.5mm and it accommodates a wire gauge of between 16-19g.
It is just the right size for a wide variety of DIY jewelry and crafts including bracelets, malas, dreamcatchers, chandeliers, Christmas tree ornaments, and party decorations.
14mm beads
The 14mm bead has about the same diameter as an AA cell or an aspirin tablet.
The hole diameter for most 14mm beads is 1.5mm-2mm. You can pair this up with a 0.024” cord or 16-17g wire.
It is good for accenting smaller sized beads in jewelry. Lighter beads will work for bracelets and necklaces if you go 14mm all the way, but gemstone beads could get heavy quickly. The size is also great as medium chandelier beads.
16mm beads
16mm beads measure 16 millimeters wide. That’s about the same size as a jeans button.
The hole diameter is 3mm-5mm in most bead types, and 14-16 gauge wire or 2.5mm diameter cord would be the matching string.
Depending on the bead’s substance, this size could be ideal for making all types of bold jewelry, earrings, bracelets, anklets, necklaces. Plastic, wood, or paper beads for example are really light. However it could get overwhelmingly heavy if you use only gemstones, or if too many are incorporated in the design.
You can also do napkin rings, mirror and vase decorations, or create toys, keychain rings, bead-covered balls etc. The sky is the limit!
18mm beads
18mm beads have 18-millimeter hole to hole length; about the same size as a dime.
Hole size could be between 3mm and 5mm and is best strung with a 14-16g wire gauge or 2.5mm cord.
This bead size is on the chunky side and is best for crafting chunky statement pieces. It is suitable for large chandelier beads, making curtain decorations, garlands, the interior of beaded beads, and wreaths.
20mm beads
20mm beads measure 20 millimeters in diameter. That’s close to the diameter of a penny but short of 0.95mm.
Hole size varies across bead types but 5mm hole diameter is expected of this bead size.
Since it is a chunky bead size, it is best for macrame, garlands, keychains, wreaths, bag charms, to accent with small beads, as a bead pendant, for making figurine heads, as a base for beaded balls, and more.
Seed beads
Seed beads are a go-to for intricate bead weaving projects. They also make beautiful embellishments for clothes, belts, and bags.
Delicate jewelry designs such as anklets and waist beads utilize seed beads as well. They also make good spacer beads for medium and large beads in bold bracelets and necklaces.
Naturally, like millimeter-sized beads, you will want to choose seed beads that are an appropriate size for your project.
We won’t go into detail since there’s only a subtle correspondence between seed bead sizes of the same numbers, but you can follow the general guidelines by standard bead sizes to gauge what approximate size of seed bead is right for your project.
How To Measure Bead Hole Sizes
You probably already know by now the importance of having the dimensions of your beads (hole length and diameter) in mind before starting to work with them. It helps you put the beads to the best use and determine the appropriate string diameter.
Unfortunately, most beads are not true to their sizes. For instance, let’s take a 2mm bead. If you pick some up you may get a true 2mm bead, or you may find yourself with beads that are actually between 0.1 and 0.5mm larger or smaller. This variance may affect the final outcome of your project when following a pattern.
You could also have an old collection of beads, perhaps of beads that you bought ages ago or received as gifts, but you may not know or cannot remember their precise sizes.
Therefore, you need to have some way of how to measure the bead size you have. The same goes for hole sizes, which may vary significantly among bead types. It is the sure-fire way of telling the true size of beads and holes and we tackle that in this part of the guide.
Using Digital Vernier Calipers To Measure Bead/Hole Size
Fortunately there are a couple of ways to determine the size of any mystery beads.
Digital vernier calipers make measuring of your bead diameter such a breeze. However, any caliper will do.
Here is how to measure your bead size using digital vernier calipers:
- Check that battery is installed and turn on digital caliper.
- Choose the mm format and reset it to zero.
- Pick up the bead between your thumb and index finger.
- Place it between the jaws of the caliper and slide the jaws back so the tips of the tool and bead touch.
- Ensure the holes are on the sides touching the jaws.
- The electronic tool will display the readings for you.
To measure the bead hole size using a digital caliper, do the following:
- Close the jaws designed to measure the internal diameter of holes. These are located above the screen and will be to the right and below the screen once you turn the calipers around.
- Holding your bead, insert the closed jaws inside the hole.
- Open the jaws as far wide as they can go by slowly moving the adjustment wheel.
- When they can’t go any further, the device will read the exact measurement of the opening.
Using a Ruler to Measure the Bead Size
Don’t have a caliper? A regular ruler with a metric (cm/mm) side will do! A cm ruler often has the mm calibration in between each cm mark.
But even if you don’t have the mm markings, you can still figure out the diameter of your beads pretty quickly.
If math and measuring were never your things, we’ve got steps to help you measure your bead size using a ruler without mm markings:
- Lay your ruler flat with the cm side on top and the 0 mark on your left.
- Put a pencil perpendicular to the ruler at the zero mark.
- Place ten beads in a row, the first hole touching the ruler and the other holes connected side by side, and record the reading. You can string them to make them stay in place.
- Divide your reading by ten to get the size of one bead. So if you get 3cm/30mm divided by 10 is 3mm. That is your bead size.
Probably though, you won’t even need to use this, since it’s pretty common to have millimeters marked on rulers. Still, if the markings ever wear off, you may be glad to know what to do in a pinch!
What about the bead hole diameter, can a ruler measure that too?
Unfortunately, a ruler cannot measure the bead hole size precisely enough. If you do not have a vernier caliper, you may use other devices such as a scale loupe or Dremel drill bits and get the measurement from the shank.
The easiest way to gauge the bead hole size without any of these tools is to have a self-made reference kit. There will be various string, cable or wire sample sizes – 2 inches each – in it to try and get through bead holes when you need to estimate the size.
Other Ways To Measure Bead Sizes
There are a few other ways to measure bead sizes as well, including:
- Use a downloadable bead size chart for reference.
- Purchase a bead size reference card or this mm/stone gauge bead sizer.
- Estimate using the everyday household items we mentioned at the beginning of the guide; pennies, nickels, etc.
- Put together a beaded keychain with the different bead size samples, each labeled with the diameter. You can use it as a reference every time you shop.
General Guide to Bead Size, By Type
Do not worry if purchasing beads online. Online stores nearly always have this information (bead hole size) readily available in the product catalog or listing description.
Still, it is also good to have a general idea of what the average bead hole sizes for the different bead types are.
So here are some general guidelines to typical bead sizes by type, in case you ever need a ballpark estimation of what you’re buying (or what you’ve just received):
- Gemstones, precious, and semi-precious stone beads
Gemstones have the most diverse bead hole sizes. The diameter will typically depend on the stone’s softness, shape, and size too. It could be anything between 0.5mm-2.0mm, increasing with bead size.
- Czech glass beads and Crystal beads
These two kinds of beads have the most consistent hole sizes, likely because they are made from a mold. They will more often than not have 0.8mm diameter holes.
- Swarovski beads
Swarovskis have three distinct bead hole sizes: a 0.6mm hole diameter for the small beads (3-5mm), 0.8mm diameter for medium-sized beads (6-8mm), and 1mm-1.5mm diameter for 10mm bead sizes or larger.
- Pearls
The classic freshwater pearl beads usually have the smallest holes. 0.5mm is the average hole size for most pearl beads. However, it is not surprising to find smaller holes of about 0.3mm or larger holes of 0.6mm and beyond.
Stringing Different Bead Sizes – What Cord Size Do You Need?
When it comes to choosing material for stringing your beads, there’s a satisfying number of options. You can opt to go with an elastic cord, monofilament cord, metallic wire, or a leather cord, among others.
Each type and brand comes in a set of diameter sizes in inches, gauge, or mm. It is up to you, the beader, to figure out which is the best one for your beads hole sizes.
When following a pattern, you’ll be guided on the ideal stringing material and size to use specific to the project, so you don’t have to sweat it.
Nonetheless, we all at some point want to let our creative juices flow and come up with our own unique designs. At that point, knowing how to match a cord, cable, wire or string to your bead hole size is pertinent.
Cord Sizing Tips and Tricks
Here are a few great tips for picking the right cord or string size for your beading project:
- As a rule of thumb, heavier beads ( which typically possess larger holes) demand a thicker cord than lighter or smaller beads.
- When combining multiple bead sizes, for example, a necklace with a mix of 3mm, 6mm, and 8mm beads, choose a string with the largest diameter that can go through the smallest bead in the design pattern.
- Always go a size smaller. When choosing a cord for beads with a 1mm hole size, opt for a 0.8mm cord. If the bead is 0.8mm in diameter, choose a 0.7mm or 0.6mm cord.
- Have a collection of various popular sizes of cords and cables as well as gauge wire and not just one size. Sometimes the middle of the hole is much narrower than the ends. As a result, you will find your chosen stringing cord or cable having trouble or even failing to go all the way through.
- Choose your ideal bead size first before buying a cord for them – and not the other way.
Bead Hole Size Chart
And finally, we’ve got some final information to share with you about hole size and how it relates to choosing the right size cord, cable, or wire.
Here is a comprehensive bead hole size chart against the maximum cord, cable wire, and gauge for your reference, thanks to Potomac Beads!
| Bead Type | Size | Hole Size | Max Cable Wire | Max Gauge | Max Cording | Shapes |
| Czech Fire Glass Polished | 3mm-8mm | 0.92mm | 0.024” | 20-21g | 0.8mm | Round, Oval |
| Czech Shape Pressed | 4-10mm | 0.8mm | 0.020” | 22g | 0.7mm | Oval, Round |
| Czech O Beads | 2✕4mm | 1.8mm | 0.040” | 16g | 1.5mm | O Beads |
| Matubo Beads | 2-3mm | 1-1.2mm | 0.036” | 18g | 1mm | 6/0 cut |
| Large Hole Czech | 6-10mm | 2.5mm | 0.050” | 14g | 2.5mm | Pony/Rings |
| Swarovski Crystals | 4mm | 0.5-0.6mm | 0.018” | 23g | 5mm | Bicone and Round |
| Swarovski Crystals | 6mm | 0.6-0.8mm | 0.020” | 22g | 0.7mm | Bicone and Round |
| Miyuki Seed Beads(11) | 1.2✕2.2mm | 0.6mm | 0.018” | 23g | 0.5mm | 11/0 |
| Toho Seed Beads (11) | 1.3✕2.3mm | 0.7mm | 0.018” | 23g | 0.5mm | 11/0 |
| Miyuki Cylinder (11) | 1.3✕1.6mm | 0.8mm | 0.020” | 22g | 0.7mm | Delica |
| Gemstones Rounds | 4-6mm | 0.5mm | 0.018” | 23g | 0.4mm | Rounds |
| Gemstones | 8mm | 0.8mm | 0.020” | 22g | 0.7mm | Rondelle |
| Large Hole Gemstones | Varies | 2.2-2.5 | 0.050” | 14g | 2.5mm | Mixed |
| Freshwater Pearls | Varies | 0.5mm | 0.018” | 23g | 0.4mm | Round |
| Large Hole Pearls | Varies | 2.2-2.5 | 0.050” | 14g | .5mm | Mixed |
| Lampwork Beads | 6-12mm | 2.2-2.5mm | 0.050” | 14g | 2.5mm | Mixed |
Bead Sizing – Review
That’s pretty much all there is to know about beads sizes.
Remember there are two scales: the mm scale for standard beads, and the Aught size for seed beads.
For standard beads, the number denoted in mm is the bead size (also diameter or the through hole length). For seed beads, a larger number is a smaller bead. Sometimes beads of the same size but different brands will have small differences in dimensions and still fall in the same size category.
Bead hole sizes vary too, but always choose a cord with a smaller diameter to the bead hole diameter. The shapes do not really matter in bead sizing.
You can utilize tools to accurately measure the dimensions. But some ordinary tools can also give you a rough idea of your bead size.
With such a wealth of knowledge on bead sizes, you’ll hopefully get treading on the right track.
So best of luck and happy beading!
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