Seed Bead Sizes Explained: 6°, 8°, 11°, and 15°
The numbering system for seed bead sizes is counterintuitive — larger numbers mean smaller beads. Once you understand why, the whole system clicks, and choosing the right bead size for a project becomes straightforward.
Why bigger number = smaller bead
Seed bead sizes come from an old measurement system: the number indicates how many beads fit in one inch laid end to end. Fit 11 beads in an inch, you have size 11° beads. Fit 15, they're size 15°. Fit only 6, they're size 6°.
The degree symbol (°) in the size notation is technically an abbreviation for "aught" (an old word for zero), written as a superscript. It has nothing to do with angles or temperature — it's just the traditional notation that stuck.
You'll also see the same sizes written with a slash and a zero: 11/0 means exactly the same thing as 11°, and 8/0 is the same as 8°. Sellers and patterns use the two notations interchangeably, so "11/0 seed beads" and "size 11 seed beads" are all the same bead.
In practice, this means: higher number = more fit per inch = each one is physically smaller.
The four main sizes
| Size | Approx. diameter | Best used for |
|---|---|---|
| 6° (6/0) | ~3.7 mm | Quick projects, children's jewelry, macramé accents, statement pieces. Easy to handle. |
| 8° (8/0) | ~3.0 mm | Bracelets, bags, larger loom pieces. Good balance of detail and speed. |
| 11° (11/0) | ~2.2 mm | The universal standard. Almost all published patterns use this size. Fine detail possible. |
| 15° (15/0) | ~1.5 mm | Extremely fine detail, miniatures, high-end jewelry. Requires thin thread and needle. |
Size 11° is the default — here's why
The vast majority of bead patterns — whether from books, PDFs, or digital tools — are designed for size 11° beads. This size hits a sweet spot: small enough to capture meaningful detail in a reasonable grid size, large enough to bead at a comfortable pace without eye strain or fine-motor fatigue.
At size 11°, a 40×40 grid produces a piece roughly 3.5 cm × 3.5 cm — ideal for earrings and pendants. A 100×80 grid produces a cuff bracelet. The math works out to usable project sizes without requiring thousands of hours of work.
If you're following a published pattern, assume size 11° unless stated otherwise.
Size 15°: when detail matters more than speed
Size 15° beads produce extraordinarily fine work. A 40×40 grid in size 15° measures under 2.5 cm across — the same pattern that makes a 3.5 cm earring in size 11° becomes a delicate 2 cm miniature in size 15°.
The tradeoffs are significant. You need size 13 or 15 beading needles (very thin, prone to bending). Thread must be thin — size 11 Nymo or 0.15 mm FireLine. Stitching is slower and requires better lighting and magnification for most people. Mistakes are harder to spot and harder to undo.
Most experienced beaders reserve size 15° for specific applications: fine facial features in a portrait piece, accent rows in a larger work, or competition jewelry where precision is the point.
Size 6° and 8°: when bigger is better
Larger beads don't mean lower quality — they mean different applications. Size 6° beads are excellent for projects that need to be worked quickly, seen from a distance, or handled by younger crafters. A 30×20 grid in size 6° produces a bold 11 cm × 7 cm piece that would take roughly 600 beads. The same grid in size 11° is a small pendant.
Size 8° sits between the two and is particularly common in two-drop peyote (where you pick up two beads at a time to speed up the work) and in woven bead bags where the slightly larger bead gives better structure.
Cylinder beads: a different system
Miyuki Delica, Toho Treasure, and Toho Aiko beads are cylinder-shaped, not round — so the round bead sizing system doesn't directly apply. These are typically sold as "Delica" or by their specific catalog size (DB-11 is approximately size 11° equivalent), but their cylindrical shape means they pack tighter and produce flatter fabric than round size 11° beads.
A pattern designed for Miyuki Delica 11° will not produce the same dimensions if you substitute round 11° seed beads. The finished piece will be slightly larger and less flat. If you're working from a published pattern, use the exact bead type specified.
Beadify's bead count estimates are calibrated per brand and size — the bead shopping list it generates accounts for the actual dimensions of Miyuki Delica, Toho, and Preciosa beads separately.
Quick reference: which size for which project?
- Earrings and pendants: Size 11° (Miyuki Delica for crispest results)
- Cuff bracelets: Size 11° standard; size 8° for quicker large cuffs
- Portrait or photo-to-bead patterns: Size 11°; size 15° for maximum detail
- Children's projects: Size 6° or 8° — easier to thread and handle
- Bags and pouches: Size 8° for structure; size 11° for fine detail
- Competition or heirloom pieces: Size 15° Miyuki Delica
Beadify calculates exact bead counts per color for any size — no manual math required.
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