Jewelry measurement

What is this necklace length called?

Two published records name necklace lengths, and they do not agree. This checker asks both, shows where they part company, and leaves a length unnamed when neither record names it.

Length

Unit

CentimetresInches

Lengths the Pearl Book leaves unnamed

These centimetre bands fall between two defined categories. The book does not say which name applies, and neither does this page.

33 to 35 cm
40 to 43 cm
48 to 50 cm
60 to 70 cm
90 to 115 cm

What the two records say

Enter a length to see what each record says.

CIBJO Pearl Book (2024)
CIBJO	cm	in	Jewelers of America (in)
Collar §5.45	25–33 cm	10–13 in	12–14 in
Choker §5.39	35–40 cm	14–16 in	14–16 in
Princess §5.169	43–48 cm	17–19 in	17–19 in
Matinee §5.118	50–60 cm	20–24 in	20–25 in
Opera §5.148	70–90 cm	28–35 in	26–36 in
Rope §5.171	115+ cm	45+ in	37+ in

The book also defines Sautoir as longer than opera and about 90 cm (36 inches), which overlaps the opera range rather than following it. It is left out of the classification above for that reason.

Sautoir §5.176 · ~90 cm (36 in)

What this does not tell you

No source read for this page says whether the length is measured with the clasp included or excluded.
Where a necklace falls on the body comes from Jewelers of America, not from CIBJO. The Pearl Book gives ranges only.
CIBJO records accepted trade practice; it is not legislation, and no evidence was found that this naming is required anywhere.
No source gives a manufacturing tolerance, or a separate scale for different wearers.

Two records, and they do not line up

The CIBJO Pearl Book is published by the World Jewellery Confederation, whose status at the United Nations Economic and Social Council is stated in the book itself, and its clause 5 is described in its own text as the terms and definitions that apply for the CIBJO standard and rules. That gives the length clauses real standing inside the document.

What the document does not do is describe wearing. It gives a range and stops. The familiar sentences about where a necklace sits — against the throat, at the base of the neck, below the bust — come from Jewelers of America, whose page gives inches only and never uses the word standard.

The numbers themselves have been stable: the 2020 edition of the Pearl Book gives the same figures for matinee and rope as the 2024 edition. Stability is not the same as agreement between sources, though, and the two records read here still put the same names on different ranges.

What the Pearl Book prints

Both the centimetre range and the inch range are printed in the book; neither is derived from the other, which is why they can disagree at the edges. The rope entry says 'about 115 cm and longer', and that word is the source's own.

Category	Clause	Centimetres	Inches
Collar	5.45	25–33 cm	10–13 in
Choker	5.39	35–40 cm	14–16 in
Princess	5.169	43–48 cm	17–19 in
Matinee	5.118	50–60 cm	20–24 in
Opera	5.148	70–90 cm	28–35 in
Sautoir	5.176	about 90 cm	about 36 in
Rope	5.171	about 115 cm and longer	45 in and longer

Source: CIBJO, The World Jewellery Confederation — CIBJO Pearl Book (2024) — kolye uzunluk siniflandirmasi · Verified on 2026-08-19

The lengths nobody names

Reading the centimetre ranges in order, the categories do not touch. There is nothing between 33 and 35, between 40 and 43, between 48 and 50, between 60 and 70, or between 90 and 115. A necklace that measures 65 cm sits in the largest of those gaps.

The checker reports that as unnamed rather than rounding it into matinee or opera. That is not a limitation of the tool: it is the state of the document. Choosing the nearer category would put a claim in a listing that the source does not support.

Sautoir is a different kind of complication. The Pearl Book defines it as longer than an opera length necklace and about 90 cm, which overlaps the top of the opera range rather than continuing past it. It is left out of the classification and shown separately for that reason.

Questions

Why does the checker give two answers for the Pearl Book?

Because the book prints two ranges for each category, one in centimetres and one in inches, and they are not exact equivalents. A length can fall inside one and outside the other. Showing a single merged answer would mean picking one of the book's own numbers over the other.

My chain is 65 cm and the checker says it is unnamed. Is that a mistake?

No. The Pearl Book's centimetre categories stop at 60 and resume at 70, so 65 cm falls in a band the document does not name. The honest listing states the measurement. Assigning it to matinee or opera would be a claim the source does not make.

Do these names apply to a metal chain?

The Pearl Book's definitions do not. Each clause describes a strand of pearls, cultured pearls or imitation pearls. The names are widely borrowed for chains, and there is nothing wrong with borrowing them, but the document that defines them does not cover metal chain.

Is this naming a legal requirement?

No evidence was found that it is. CIBJO describes its own task as recording accepted trade practice, complementing existing fair trade legislation, and Jewelers of America does not call its list a standard. The technical committee responsible for jewellery standards lists ring sizes in its published scope and does not mention necklace length.