Jewelry Size Guide: Rings, Bangles, Chains & Earrings

Wholesale orders live or die on size accuracy. This page sets out the size systems we work in, the tables we quote from, and how a size gets confirmed in writing before tooling starts.

Ring sizes: the inner diameter is the spec

Conversion charts differ by country and by source, so we treat the measured inner diameter in millimetres as the contractual specification. The US, UK and EU columns below are reference values only. If a size is ever disputed on delivery, it is checked against the diameter on the spec sheet — not against a letter.

US	UK	EU	Inner diameter (mm)	Inner circumference (mm)
4	H	47	14.9	46.8
4.5	I½	48	15.3	48.0
5	J½	49	15.7	49.3
5.5	K½	50	16.1	50.6
6	L½	52	16.5	51.9
6.5	M½	53	16.9	53.1
7	N½	54	17.3	54.4
7.5	O½	55	17.7	55.7
8	P½	57	18.1	57.0
8.5	Q½	58	18.5	58.3
9	R½	59	18.9	59.5
9.5	S½	61	19.4	60.8
10	T½	62	19.8	62.1
10.5	U½	63	20.2	63.4
11	V½	65	20.6	64.6

US 4–11 is our standard range, half sizes included. US 12 and above are quoted on request. EU conventions vary between countries, so quote the diameter whenever there is any doubt.

How to measure a ring you already have

Do not measure the outside of the band — the plating and the design both add thickness. Measure the inner diameter across the widest point with a caliper, or press the ring onto a ruler and read the inside edge to the opposite inside edge.

Without a caliper: cut a strip of paper, wrap it snugly around the inside of the ring, mark where it overlaps, and measure the strip. Divide that circumference by 3.1416 to get the diameter. Anything within 0.2 mm is close enough to pick a size; below that, send us the ring.

Bangles and cuffs

Bangles are quoted by inner diameter, not by a letter size. A women’s bangle typically sits between 55 mm and 62 mm; below that it will not pass the widest part of the hand, above it will rotate freely on the wrist. Every style in our range has its measured diameter listed, and custom diameters are cut to order.

• Open cuffs: specified by the inner diameter with the gap closed, plus the gap width itself. A cuff can be eased open at the counter, so the gap is set slightly wider than the wrist measurement.
• Hinged bangles: the clasp is the failure point, not the size. Each batch is opened and closed repeatedly before packing.
• Rigid closed bangles: the opening must clear the knuckles. Measure the hand at its widest, not the wrist.

Chain and bracelet lengths

Bracelet lengths are quoted in centimetres on the spec sheet and in inches in the listing. Extender chains add 30–50 mm where the design allows.

Bracelet (cm)	Inches	Necklace (cm)	Inches
16	6.3	40	15.7
17	6.7	45	17.7
18	7.1	50	19.7
19	7.5	55	21.7
20	7.9	60	23.6
21	8.3	—	—

Length is measured end to end including the clasp, before any extender. Chain gauge, pendant drop and clasp type are specified per design so your listing can publish exact measurements.

Earring posts and findings

• Post gauge: 0.8 mm (20G) is our standard. Heavier drops and tassel pieces are quoted at 0.9 mm or 1.0 mm so the earring does not tilt forward.
• Closures: butterfly (friction) as standard, screw-back and lever-back on request. Hypoallergenic stainless steel posts are the default; 925 silver posts are available.
• Ear cuffs: held by metal tension alone, so the gap and wall thickness have to match. Each cuff is opened and closed by hand before packing; a cuff that has gone soft in the plating bath is rejected rather than shipped.
• Weight: every pair is weighed before packing, because weight is what decides whether a drop earring hangs correctly.

Tolerance, sizes and minimums

Cast rings hold roughly ±0.2 mm across a production run. We check a sample from each batch with a ring gauge and record the result; if a run drifts, it is re-sized before plating, not after. Because sizing happens before finishing, a size cannot be changed once the piece is plated.

The minimum order is 30 pieces per design, and that 30 can be split across sizes. Sampling runs 7–12 days; bulk production 20–35 days after sample approval.

Related references

• Stone guide: CZ, nano stone, lab-grown diamond and natural — what each stone family costs and how it has to be set.
• How we quote wholesale orders — what sits inside a price, including the sizing work described above.
• Ring sizing standards and tolerance — the deeper note on measurement method and batch drift.
• All resources for wholesale buyers — the full reference index.