How bead bracelet sizing works
A bracelet size calculator turns three things into a plan: how big your wrist is, how loosely you want the bracelet to sit, and how much string each bead uses. This bead bracelet sizing calculator handles that arithmetic so you can buy the right number of beads and cut the right length of cord the first time.
Measuring your wrist
Wrist size is the circumference of your wrist at the point where the bracelet will sit, usually just above the wrist bone. Use a flexible tape or a strip of paper, keep it snug without squeezing, and read the number where the ends meet. Measure the wrist the bracelet is for, since the two wrists can differ by a few millimetres. For a stretch bracelet, also check that your hand can pass through the finished circle.
Fit allowance: snug, standard, loose
Fit allowance is the extra length you add to the wrist measurement so the bracelet is comfortable. The calculator uses allowances that are common in jewelry making for beaded bracelets.
- Snug, +10 mm (0.4 in): sits close and stays in place. Good for stretch bracelets and stacks.
- Standard, +17 mm (0.7 in): moves a little and slides over the hand without a struggle. A sensible default.
- Loose, +27 mm (1.1 in): drapes and shifts. Suits heavy beads, charms and clasped designs.
These are starting points. Thicker beads need more room because they cannot flex around the wrist, so go up a step if you are using 10 mm beads or larger.
Bead diameter and bead count
Bead diameter is the width of the bead, measured in millimetres. Bead count is the length that must be filled with beads divided by the length each bead occupies on the string:
Bead count = (bracelet circumference − clasp − accent beads) ÷ (bead diameter × shape factor)
The result is rounded to the nearest whole bead. Because each bead changes the length by its own size, a bracelet of 8 mm beads can only land on lengths 8 mm apart. The calculator shows the finished length for the rounded count so you can see how close it gets.
Elastic and stretch considerations
Stretch cord is usually 0.5 to 1.0 mm thick, and it needs a knot and a short tail, which is what the elastic allowance covers. Cut that extra length, not an extra bead. Elastic stretches when you put the bracelet on, but it returns to its relaxed length, so size the strand for the relaxed circumference. Pre-stretch new elastic a few times before stringing so the bracelet does not loosen after the first wears. Heavier beads and larger holes call for thicker cord.
Why bead shape affects final sizing
The count depends on how much string a bead covers, and shape changes that. A round bead covers its diameter. A rondelle or disc is wide but thin, so it covers far less string and you need more of them. Barrels, ovals and tubes are longer than they are wide, so each one covers more and you need fewer. Faceted beads can sit a little tighter because their edges nest. The shape factors here are estimates, so for unusual beads, string a few and measure them.