Bead Strand Count Calculator
Work out how many beads you need to fill a strand of a given length from the bead diameter and any spacer gap, with an overage cushion.
How it works
Length (mm) = inches × 25.4 or cm × 10 · Beads = ⌊length ÷ (bead + gap)⌋ · Buy = ⌈beads × (1 + overage%)⌉
Each bead (plus any spacer gap) occupies a fixed run of the strand, so the count is simply the strand length divided by that per-bead distance. Working in millimetres keeps bead sizes and lengths consistent. Beads are sold in strands or tubes and colours vary between dye lots, so an overage cushion means you never run one bead short of finishing a piece.
Worked example
An 18-inch strand is 18 × 25.4 = 457 mm. With 6 mm beads and no gap, 457 ÷ 6 = 76 beads. Adding a 10% cushion, buy 84.
Frequently asked questions
Should I include the clasp in the length?
Subtract the clasp and any findings from the finished length first, then bead the remaining span. This calculator counts beads for the length you enter, so enter the beaded portion.
How do I handle mixed bead sizes?
Run the calculator once per size using the length that portion will cover, then add the counts. The per-bead distance must match each bead’s own diameter.
Why add overage?
Beads chip, roll away, or arrive slightly off-colour between batches. A 10–15% cushion saves a second shopping trip mid-project.
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This calculator is for educational purposes. Double-check important results before acting on them.