Seed Beads Sizing 101

Decoding 11/0, 10/0 & Friends

Seed beads come in a glorious range of sizes, shapes, and personalities. But what do numbers like 11/0 or 8/0 actually mean? This quick guide explains the numbering system, how sizing varies by brand and style, and how to choose the right bead for stringing, bead weaving, and embroidery.

What does “aught” mean?

The size numbers (like 11/0 or “eleven‑aught”) are historical. As the number goes up, the bead goes down in size. So 15/0 is tiny; 6/0 is nice and chunky. The system isn’t perfectly standardized across manufacturers—that’s why 11/0s from different brands can look and behave slightly differently.

Quick size chart (approximate)

These measurements are helpful guidelines—not absolute rules. Tolerances vary by brand, finish, and style.

Common Size	Approx. Outer Ø	Approx. Hole Ø	Beads per inch*	Typical Uses
15/0 (very small)	~1.5 mm	~0.6–0.7 mm	25–28	Detail work, bezels, fine edging
11/0 (popular standard)	~2.0–2.2 mm	~0.8–1.0 mm	18–20	Weaving, peyote, brick, loom, embroidery
10/0	~2.3–2.5 mm	~0.9–1.1 mm	16–18	Weaving with a slightly bolder look
8/0	~3.0 mm	~1.0–1.2 mm	12–13	Beginner‑friendly weaving, stringing accents
6/0 (larger)	~3.8–4.0 mm	~1.2–1.5 mm	8–10	Stringing, kumihimo, knitting, quick projects

*Beads per inch is measured when beads are strung snugly side‑by‑side. Your mileage may vary with thread tension and brand.

Czech vs. Japanese (and why it matters)

Japanese seed beads (e.g., Miyuki, TOHO) are known for precision and consistent hole sizes—great for intricate weaving and uniform patterns.
Czech seed beads (e.g., Preciosa Ornela) have a classic, slightly rounder profile that adds organic texture—beautiful for stringing and bead embroidery.
Because shapes and finishes differ, samples from different brands can sit differently in a stitch. If a pattern calls for a specific brand, it’s often for this reason.

Hole size, thread & needle choices

Thread: For 11/0s, most makers use size B or D nylon beading thread, FireLine 4–8 lb, or similar micro‑cords depending on technique.
Needles: Size 10–12 beading needles work for 11/0; drop to size 12–15 for 15/0, and size 10 for 8/0 and 6/0.
Multiple passes: Japanese 11/0s typically allow several passes of fine thread; Czech 11/0s are more variable—test a few before committing to a dense stitch.

Which size for which project?

15/0: bezeling cabochons, tiny accents, fine netting.
11/0–10/0: the workhorse sizes for peyote, brick, loom, RAW, and most detailed embroidery.
8/0: beginner weaving, spacer beads, textured stringing, seed bead crochet.
6/0: bold strands, kumihimo, knitting, memory wire, quick statement looks.

Shopping tips & storage sanity

When color‑matching, buy enough up front—dye lots and finishes can shift slightly over time.
Label by brand, size, and color code so you can reorder easily.
Mind finishes: metallics and AB coatings can affect hole size and durability; treat high‑shine finishes gently.

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