Necklace Length Calculator
Necklace lengths have names: choker 40 cm, princess 45 cm, matinee 55 cm, opera 75 cm, rope 105 cm. A choker still has to clear the neck, usually 33–35 cm, while a princess sits on the collarbone and a matinee below the bust. Once the target is chosen the rest is subtraction: on a 45 cm necklace the clasp and crimps take 20 mm, leaving 430 mm for beads, so 8 mm rounds give 53 beads and a finished 44.4 cm. Skip that subtraction, divide 450 by 8, string 56 beads, and the necklace closes at 46.8 cm — past the length you wanted. The wire figure alongside is the target plus 10 cm, the tails you feed back through the crimps at each end.
Your numbers
Beads
53
Strand length
44.4cm
Wire length
55cm
Formula
Beads = ⌊(Finished length × 10 − Clasp allowance) ÷ Bead diameter⌋
The count rounds down; the spare millimetres gather at the clasp and there are no half beads. Printed diameters are nominal and natural stone varies by half a millimetre a bead, so expect to be one or two out — lay ten beads along a ruler before stringing and you have the real diameter. The clasp allowance varies more than anything else: a small lobster is 10 mm, a magnetic ball clasp or one with an extender chain runs past 40 mm. Necklaces also hang forward under their own weight and read slightly longer at the front, so when in doubt take a centimetre off the target.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Finished length (cm)The length when finished. | 45 | 0 and up |
| Bead diameter (mm)One bead across the outside, not the hole. | 8 | 0 and up |
| Clasp allowance (mm)Length taken by the clasp and crimps, measured end to end when closed. | 20 | 0 and up |
Step by step
Quick reference table
Results when only Finished length (cm) changes and everything else stays put.
| Finished length (cm) | Beads | Strand length (cm) | Wire length (cm) |
|---|---|---|---|
| 22.5 | 25 | 22 | 32.5 |
| 33.8 | 39 | 33.2 | 43.8 |
| 45 | 53 | 44.4 | 55 |
| 67.5 | 81 | 66.8 | 77.5 |
| 90 | 110 | 90 | 100 |
What each result means
| Result | At default values |
|---|---|
| BeadsBeads it takes; adding a gap between them lowers it. | 53 |
| Strand length (cm)The finished strand, excluding the clasp. | 44.4 |
| Wire length (cm)Wire needed, before what you trim and waste. | 55 |
Common mistakes
The count rounds down; the spare millimetres gather at the clasp and there are no half beads. Printed diameters are nominal and natural stone varies by half a millimetre a bead, so expect to be one or two out — lay ten beads along a ruler before stringing and you have the real diameter. The clasp allowance varies more than anything else: a small lobster is 10 mm, a magnetic ball clasp or one with an extender chain runs past 40 mm. Necklaces also hang forward under their own weight and read slightly longer at the front, so when in doubt take a centimetre off the target.
Glossary
- Finished length
- The length when finished.
- Bead diameter
- One bead across the outside, not the hole.
- Clasp allowance
- Length taken by the clasp and crimps, measured end to end when closed.
- Beads
- Beads it takes; adding a gap between them lowers it.
- Strand length
- The finished strand, excluding the clasp.
- Wire length
- Wire needed, before what you trim and waste.
Frequently asked questions
Q. How is Necklace Length Calculator calculated?
Beads = ⌊(Finished length × 10 − Clasp allowance) ÷ Bead diameter⌋ — Necklace lengths have names: choker 40 cm, princess 45 cm, matinee 55 cm, opera 75 cm, rope 105 cm. A choker still has to clear the neck, usually 33–35 cm, while a princess sits on the collarbone and a matinee below the bust. Once the target is chosen the rest is subtraction: on a 45 cm necklace the clasp and crimps take 20 mm, leaving 430 mm for beads, so 8 mm rounds give 53 beads and a finished 44.4 cm. Skip that subtraction, divide 450 by 8, string 56 beads, and the necklace closes at 46.8 cm — past the length you wanted. The wire figure alongside is the target plus 10 cm, the tails you feed back through the crimps at each end.
Q. Can you walk through an example?
With Finished length 45cm, Bead diameter 8mm, Clasp allowance 20mm, the answer is Beads 53.
Q. What do I need to enter?
Enter Finished length, Bead diameter, Clasp allowance. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Finished length (cm) moves the answer to Finished length (cm) 22.5 → Beads 25 and Finished length (cm) 90 → Beads 110. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
The count rounds down; the spare millimetres gather at the clasp and there are no half beads. Printed diameters are nominal and natural stone varies by half a millimetre a bead, so expect to be one or two out — lay ten beads along a ruler before stringing and you have the real diameter. The clasp allowance varies more than anything else: a small lobster is 10 mm, a magnetic ball clasp or one with an extender chain runs past 40 mm. Necklaces also hang forward under their own weight and read slightly longer at the front, so when in doubt take a centimetre off the target.
Related calculators
Materials differ in density and absorption. If your label states a figure, use it — the defaults here are only common values.