Purchased a handful of 8/0 for a bracelet, took the tube out of the package, and they looked a lot smaller than the last 8/0 you received? Occurs more than any would like to mention. That discrepancy is the entire reason why individuals spend cash on seed beads, and it's the reason why the sizes of seed beads is confusing to newest comer and experienced alike. The package label states one thing. The seed bead in your hand states differently.
Quick Answer: What an Aught Size Actually Tells You
The abbreviated explanation: AUS (the little number over the slash-zero, 11/0 in general) is a historical tag, not an actual size. An identifier. Not a size. An increase in number generally signifies a smaller size bead (reverse logic I know). And the actual millimeter number varies by manufacturer, by shape, and by the item you have in your hands.
How the 6/0, 8/0, 11/0 and 15/0 System Works
This is the notation. Seed bead sizes are written with a slash and a zero. For example 6/0, 8/0, 11/0, 15/0. You'll also hear them pronounced as "six-oh" or "eleven-oh". Same thing.
Part 1.2, the 'counterintuitive' bit that confuses people. The numbers go backwards from what your intuition thinks (really, backwards). A 6/0 is a big bead. An 11/0 is tiny. A 15/0 is tiny, the sort you squint at under a lamp. So as the 'aught' number goes up, the bead gets smaller. Check twice if you have to, because I can say with certainty that everyone gets this wrong in their first week!
Why does a backwards label make it? It's actually because it is really handy for rough comparison, and once you have direction running around in your head it makes a really quick shorthand between makers, so when someone says "grab some 11/0 for this" you instantly know the ballpark without having to get out a ruler or have second thoughts. What it will not do is give you a guaranteed final fit, for that you'll still need to measure, or compare to the source. Just a quick reminder about notation:
- 6/0 the big ones that take a long time to string (roughly the biggest ones you find in common seed beads).
- 8/0, a can-do mid-sized workhorse.
- 11/0, the most versatile all-rounder.
- 15/0, fine, level of detail, small holes.
Manufacturer-Specific Seed Bead Size Chart
This is where a plain seed beads size chart really comes in handy. And where it can also get you into trouble. Used improperly, this kind of chart is easy to read incorrectly. The chart below is specific to each manufacturer. It is not a universal conversion. Each value remains attached to its producer, its shape, and its origin. Wondering what 11/0 seed beads in mm, or 8/0 seed beads in mm, or 6/0 seed beads in mm are? Read across the row, not down a single "correct" column.
| Manufacturer | Shape / product family | Aught | Approx. mm | Tolerance (when supplied) | Min. hole (when supplied) | Approx. pieces per kg (when supplied) | Source |
|---|---|---|---|---|---|---|---|
| TOHO | Round | 11/0 | approx. 2.2 mm | slight size deviation allowed | not supplied | approx. 105,300 | TOHO sample card / grain-bead data |
| TOHO | Round | 8/0 | approx. 3.0 mm | slight size deviation allowed | not supplied | approx. 41,800 | TOHO sample card / grain-bead data |
| TOHO | Round | 15/0 | not supplied | not supplied | not supplied | approx. 269,400 | TOHO grain-bead data |
| TOHO | Round | 6/0 | not supplied | not supplied | not supplied | approx. 16,700 | TOHO grain-bead data |
| PRECIOSA | Rocaille, round / round-hole | 15/0 | approx. 1.5 mm | 1.4 to 1.5 mm | 0.40 mm (transparent and opaque) | approx. 625,000 | PRECIOSA Rocaille sample card, p.7 (June 2013) |
| PRECIOSA | Rocaille, round / round-hole | 11/0 | approx. 2.1 mm | 2.0 to 2.2 mm | 0.70 mm transparent / 0.60 mm opaque | approx. 130,000 | PRECIOSA Rocaille sample card, p.7 (June 2013) |
| PRECIOSA | Rocaille, round / round-hole | 8/0 | approx. 2.9 mm | 2.8 to 3.2 mm | 0.90 mm transparent / 0.80 mm opaque | approx. 42,000 | PRECIOSA Rocaille sample card, p.7 (June 2013) |
| PRECIOSA | Rocaille, round / round-hole | 6/0 | approx. 4.1 mm | 3.7 to 4.3 mm | 1.10 mm transparent / 1.00 mm opaque | approx. 13,300 | PRECIOSA Rocaille sample card, p.7 (June 2013) |
Notes for readers: Note the identical 11/0 label placed both on an 11/0 round and an 11/0 rocaille round at just about .08 to .09 of an inch. It is close but not quite the same. One-tenth of a millimeter seems nothing on the page but the slight variations will pile up in a string of closely placed beadwork. That is why no one-size-fits-all bead chart necessarily serves you well. Close; but not close enough when it accumulates. One-tenth of a millimeter. Add it to your hundred and then multiply it by your length of string. Miyuki clearly says on its "Miyuki Size & Shape" page that their millimeter measurements "provide you with the information to determine approx size.", which is something handy to keep in mind when using any chart.
Why the Same Aught Number Can Measure Differently
Manufacturer and product-family conventions
So every maker ends up with its own set of sizing lines. Own baseline. Own historical reference point. An 8/0 tag on a round and an 8/0 on a rocaille and an 8/0 on a cylinder can all be miles apart in terms of their actual size because the sizing family that each belonged to had already established its own baseline by the time the first aught was actually printed on the tag. So assuming that something labeled 8/0 is the same size in every family is just about the best way to get it wrong. More often than not. Same number, different reference point.
Shape and hole style
Rounds, cylinders, three-cuts. They sit in a different position. They cut threads in a different way. The opening has a different profile even when two are at the same aught. Shape is not an afterthought. It has an impact on the behavior of the bead the instant a thread passes through.
Coating or finish
A coating just puts a delicate coat on. Can make the usable opening that bit smaller, so a coated bead and uncoated one at the same size do feel slightly different on the needle. Slight difference, significant difference.
Production tolerance and lot variation
The beads are varied even at one size, and the color lots may change the mean. The producer hence publishes a range rather than a figure. PRECIOSA, for example, publishes a 11/0 rocaille round at approximately 2.0 to 2.2 mm, giving you the honest spread from the get-go.
Range is not laziness. Range is the nature of a physical thing.
Hole Size, Needle, Thread and Repeat Passes
And here is the difference that keeps most projects out of trouble. Two measurements. Not one. Outside diameter and the hole diameter are two different measurements. The outside is what the bead appears to be. The opening is what counts if your thread and needle will get through, and how many times.
What size string for seed beads, then? Not one. Not any. And anyone who tells you one is (probably) making a guess. The best solution is a checking technique, because a seed bead is generally not pierced a single time, and in stitches like peyote or brick the same bead is pierced many times as the pattern doubles back itself, all those several passes silently vying for the same unchanging hole till one of these times the needle just won't go. (Needle needs to fit also, not just the thread.)
Things That Take Up the Space You Start With:
- Outside diameter (width of bead overall);
- Hole diameter, the opening (this is most important!);
- Needle width;
- Width of thread/cord;
- Double threading (plus knot);
- Repetitions of pass of the stitch;
- Absorbing coatings and finishes;
- Movement and tension of project (Tight fabric requires less space).
It takes thirty seconds. Thirty. That's all. Thread the real needle, with the real thread. Run it through the one bead. As many times as the pattern says to. Not once. As many times as the stitch is asking for. If you have to do it three times, make the bead larger or the thread thinner. That simple little measure will save you miles of unpicking of the whole row later on, every single time! Thirty seconds now, or a ruined evening later (and I have had a ruined evening more than once).
Choose a Size by Project Constraints, Not a Universal Best Size
No one best size. None. Just what the project needs. Begin with the constraint, not with a thing somebody posted online.
What size seed beads for bracelet? 8/0 or 11/0 seem to be the most popular since they string quickly and look good on the wrist (although a thicker, 6/0 size can be also lovely on a child's stretch bracelet since durability is king). What size seed beads for embroidery? That is a different matter entirely: a more delicate size, like 11/0 or 15/0, lay flatter and are better for the intricacies of the design, but again the fabric weight and whether your needle fits come into play. Can you see the difference in reasoning based on the project? That is the trick.
| Project context | Main size / fit constraint | What to check | Why no universal size can be assigned |
|---|---|---|---|
| Bracelets | drape and hole strength on the cord | cord diameter vs. hole; how it sits on the wrist | cord type and wrist movement change the size that works |
| Embroidery | low profile, flat lay, consistency | fabric weight; needle fit; finish | fabric and design details determine size, not the label |
| Earrings | weight and visual balance | overall weight; how it hangs | design and metal findings shift the ideal size |
| Cross stitch | fitting the fabric count | flush fit to the grid; holes and floss | the fit depends on the fabric count, per piece |
It's logic that holds true no matter what: friendship bracelets, waist beads, rings, tassel work, bead knitting, sequin projects, safety pin projects, choker necks, even ciphers done in Morsesque rhythms - each of those dimensional questions somehow ends up having the same, short few and only physical realities, i.e. weight, droopiness, hole strength, and then how the bead sits into the cord or onto the fabric and not in some digital reference a stranger shared is the "correct" height for a given craft. This list always remains unchanged. Nothing more here than the shopping decision You Weigh First.
How Many Seed Beads Are in a Gram?
"How many seed beads in a gram?" is a perfectly reasonable planning question, and there is a perfectly reasonable way to estimate it, without resorting to a 'gospel' figure. Perfectly reasonable question. Perfectly reasonable answer. If a manufacturer states pieces per kilogram, divide it by 1,000. That is the whole method. So then how many 11/0 seed beads in a gram, from TOHO's stated figure of 105,300 pieces per kilogram? Just over 105 (and that is enough for planning)!
| Manufacturer | Shape / family | Aught | Approx. pieces per kg | Approx. pieces per gram (÷ 1,000) |
|---|---|---|---|---|
| TOHO | Round | 15/0 | approx. 269,400 | approx. 269.4 |
| TOHO | Round | 11/0 | approx. 105,300 | approx. 105.3 |
| TOHO | Round | 8/0 | approx. 41,800 | approx. 41.8 |
| TOHO | Round | 6/0 | approx. 16,700 | approx. 16.7 |
Everything listed here are all estimates. Each one of them. And they can be off by a fair amount, as shape, size, finish, color, and production batch can each sway the totals in their own directions and all the real world adds sample loss, broken pieces and simple project waste on top of whatever the calculation gave you.
Use your result as a planning number, not a definite. And do not rely on it to answer packaging questions, the grams in a tube, a generic 17-gram pack, a 100-gram quantity. Those all depend of the specific product and its own lot, which is a whole other project.
How to Read a Listing Before You Order
Pre-purchase introspection - Before you put anything in your shopping cart, give your listing a second review, against a brief sanity test. To do your sanity check, you need no more than 30 seconds. This, by itself, is what's going to avoid 99% of those heartbreaking "hold on a second, they look tiny" returns that zap your time and your shipping buck.
- current material statement;
- manufacturer or product family, when it is specified;
- shape;
- aught notation;
- approximate outside diameter;
- rough hole measurement;
- finish or coating;
- quantity;
- current availability;
- your actual choice of needle, thread, and number of passes;
- the particular item and option, with the intention of ordering more in the future.
When you go to lay options side by side with the list, comparison shop the shop the current Seed Beads collection and look at each product page because the listing is the one that tells you what you are actually buying, not a reference chart!
Common Seed Bead Sizing Mistakes
Most sizing grief comes from a handful of repeat offenders. Same few, over and over. Pair each with the fix (in no strict order):
- No 1: Treats an aught as actually its Millimeter. That's just a label, not a caliper reading so the moment you begin to treat one maker's quoted 2.2 mm as a divine width for each 11/0 on this planet you've already managed to mismatch. First measure or research.
- 2: mixing rows of manufacturer between each other. Never mixing a TOHO figure in a PRECIOSA row. Keep all value one by one with own maker!
- Number 3: ignoring shape. A round and a cylinder at the same aught are not the same (they are really) and so read shape with the number.
- Confusing hole diameter with outside diameter. Two separate measurements. The opening is what your thread lives in.
- Chooses thread without accounting for duplicate iterations. Testing the actual iteration count before going to a full design.
- Assumes 2 mm or 3 mm always translates to one aught. Does not reverse cleanly. One given millimeter can be one or several labels depending on maker and shape.
- Applying one pieces-per-gram count for all items. It varies by size, shape, finish and lot. Recalculate for each product.
- Test small before placing large order. Buy only what you're about to test the actual product. Restock from what you tested. Cheesy advice. Will save you the most cash.
Seed Bead Size FAQ
Is an 11/0 consistent in measurements of mm?
No, not really. In every batch one round 11/0 of a certain brand might measure just over 2.2mm whereas another company's rocaille round may be just under 2.1mm. Nearly twins, but not quite. Always be sure to check the source and shape rather than assuming the label will be the same across the board.
Is the aught number the same as the hole size?
They are separate. Separate. The aught gives the general idea of the bead size, but the hole is its own thing and is often listed separately. I may buy beads that are the right size but the hole is too small for my thread, that's what the hole is for.
Is it possible for me to revert a 2 mm or 3 mm to one aught number?
not cleanly. A single millimeter can have a number of different aught labels depending on the shape and the maker. There is not one-to-one conversion from the number to the universal label. Instead go from the maker's row to the number.
Why isn't it just a matter of picking the right needle and thread from the ought label?
What the tag is describing is rough size (not the usable opening). Shape, finish and number of passes your stitch takes changes what will fit. The surefire way is a quick physical test with your real needle and thread.
Why are the different bits per gram estimates so all over the place?
Size, shape, finish, color, and lot change affect count; then damage and project spoil chip away at it. The divide-by-1000 formula gives a realistic planning number, but not a guaranteed useful yield!
What to take note after test a working bead?
Keep the maker, shape, ought, your measured outside dia and hole, and the thread and needle that did the deed, as well as the number of passes. That little file makes a hit and miss find into a reorderable line.
Your Next Step: Compare, Test, Then Restock
Time to put into action. Check the manufacturer numbers against what you are making, look up the current listed product details pdf you have opened, measure your needle and thread, the repeat pass, the scale, the weight, test a sample then record and label the item and result precisely before adding to your stock. First track yourself: go to the Seed Beads collection page for live product specific guidance, general bead testing information for outside-diameter and hole way points, and the full collection over at ZoeDIY. Measure once. Buy right. Prevent the returns.
