How many 6 mm beads do I get from 16 inches?
For a 16 inch finished necklace, allow 1.5 inches for clasp and findings, so the beaded run is about 14.5 inches. That gives about 61 of 6 mm beads or about 46 of 8 mm beads. An 18 inch necklace uses about 70 of 6 mm or about 52 of 8 mm. A 16 inch choker in small rondelles reads tight and uniform when you plan for a few spares beyond those counts.
For strands sold by length, a 15 to 16 inch strand of 6 mm rondelles carries about 65 to 70 beads, of 8 mm about 48 to 52, and of 4 mm about 95 to 100. Standard Jaipur strands run 13 to 16 inches, and 13 inch strands are common for faceted rondelles. One strand covers a bracelet or choker, and two strands make a long necklace. I, Anish Tandon, still do this math on a pad before packing show orders.
What cull rate should I expect by stone?
We see the fewest culls on hard stones with tight structures. Sapphire and black spinel are Mohs 9 and 8, so chips and broken drill exits are uncommon when cut cleanly. They suit daily-wear pieces; see our sapphire guide and black onyx and black spinel guide.
Tourmaline and onyx trend to a moderate cull. Tourmaline is Mohs 7 to 7.5 and takes a crisp facet, but inclusions and pleochroic darkness can push a few beads to the spare cup. Onyx is tough in wear, yet larger fancy cuts can show abraded points.
Expect higher cull on brittle or cleavable stones. Emerald is beryl, but it is often fractured, so plan to pull any beads with open jardin at the hole. Feldspars like labradorite and rainbow moonstone have perfect cleavage, so edge chips happen. Ethiopian Welo opal is softer, so you will set aside more beads with surface crazing or dull spots.
What cull rate should I expect by shape?
Rondelles and rounds usually yield the best, especially in small sizes. The drill is central, faces are short, and minor symmetry issues hide well on the strand. That is why rondelles are our workhorse for strung designs.
Heishi read as a continuous column, so thickness variance and edge chips show. Budget extra for spares and expect to sort for consistent disc height. See our heishi notes for use in stacks.
Top-drilled points need more spares. Pears, marquise and diamond cuts concentrate stress at the tips and drill exits. We inspect those first and keep the best pairs for earrings or the center of a graduated necklace.
How many beads do I need for common lengths?
Bracelet math is tight. A 7.5 inch bracelet has about 6 inches of beads: 4 mm about 38, 6 mm about 25, 8 mm about 19, 10 mm about 15. A 7 inch bracelet has about 5.5 inches of beads: 4 mm about 35, 6 mm about 23, 8 mm about 17, 10 mm about 14.
Necklace counts scale with length. A 16 inch choker uses about 61 of 6 mm or about 46 of 8 mm. An 18 inch necklace uses about 104 of 4 mm, about 70 of 6 mm, about 52 of 8 mm, or about 41 of 10 mm. Graduated sets need extra for matching by size and tone.
Standard strands from Jaipur cutters measure 13 to 16 inches. A single 13 inch faceted-rondelle strand covers a bracelet or choker. Two strands make a longer piece with room for spares. Knotting between beads adds about 1 mm per knot and increases finished length.
How do I spot and sort culls fast?
Set up bright side light and a 10x loupe. Scan drill exits first, then roll each bead to catch cracks, pits or cloudy zones. For labradorite and moonstone, tilt to confirm that the flash spans the face, not just a corner.
Check hole size and straightness on the cord or wire you plan to use. Ream only lightly to remove burrs. Keep a small cup for culls and a second cup for borderline beads that can hide near the clasp or in earrings. Anish here: drill exits tell the truth fastest.
Does graduation or knotting change my yield?
Yes. Graduated pears, marquise and slices include smaller end beads that shorten the beaded run if you skip them. Plan an extra inch or two of beads for pairing and symmetry, especially on earrings and matched collars.
Knotting adds about 1 mm per knot, which can push a choker into a longer length. Heishi strands show thickness variance more than rondelles, so string a test inch and count before cutting wire. For slices and slabs, align drill orientation and thickness so the strand sits flat. We often link slices between spacers for stability.