Size errors are the most common cause of wholesale returns in bridal. Use this guide to specify sizes unambiguously on your purchase order.
Ring size conversion chart
| US | UK / AU | EU (ISO) | JP | Inner diameter (mm) | Inner circumference (mm) |
|---|---|---|---|---|---|
| 4 | H | 47 | 7 | 14.9 | 46.8 |
| 5 | J 1/2 | 49 | 9 | 15.7 | 49.3 |
| 6 | L 1/2 | 52 | 11 | 16.5 | 51.9 |
| 7 | N 1/2 | 54 | 14 | 17.3 | 54.4 |
| 8 | P 1/2 | 57 | 16 | 18.1 | 57.0 |
| 9 | R 1/2 | 59 | 18 | 18.9 | 59.5 |
| 10 | T 1/2 | 62 | 20 | 19.8 | 62.1 |
| 11 | V 1/2 | 65 | 23 | 20.6 | 64.6 |
| 12 | Y | 67 | 25 | 21.4 | 67.2 |
Always confirm which standard your order uses. A US 7 and an EU 54 are close but not identical, and a millimetre of difference is the difference between a sale and a return.
How to measure a ring accurately
- Measure the inner diameter of an existing ring with digital callipers across the widest point, at room temperature.
- Do not measure a ring that has been resized — the metal thickness is unreliable after sizing.
- If measuring a finger, use a proper ring gauge rather than string or paper, which stretch and distort.
- Measure at the end of the day, when fingers are at their largest.
- For wide bands above 6 mm, add a quarter size: wider bands sit higher on the finger and need slightly more room.
Necklace lengths
| Name | Length | Where it sits |
|---|---|---|
| Choker | 35–40 cm (14–16 in) | At the base of the neck |
| Princess | 43–48 cm (17–19 in) | Just below the collarbone — the best-selling length |
| Matinee | 50–60 cm (20–24 in) | On the chest |
| Opera | 70–85 cm (28–34 in) | Below the bust |
| Rope | 100 cm+ (40 in+) | Doubled or knotted |
Bracelet and bangle sizes
- Standard stock lengths: 16 cm (6.3 in), 17.5 cm (6.9 in), 18 cm (7.1 in), 19 cm (7.5 in).
- Highest-turnover length in Western markets: 17.5–18 cm.
- Tennis bracelets: a 7-inch length covers the majority of buyers; stock 6.5, 7 and 7.5 in at roughly 2:5:3.
- Bangles: sized by inner diameter, commonly 58–65 mm.
Specifying sizes on a wholesale order
State the standard and the size on every line: US 7 / 17.3 mm internal. If you want us to build a size curve for your market, tell us the channel — bridal retail, online, marketplace — and we will propose a distribution based on comparable markets. Sizes are always confirmed on the approval sheet before production.
Building a size curve for a new market
If you are entering a market for the first time, do not order a flat distribution across sizes. Ask us for a proposed curve based on comparable markets and channels, then commit a fixed proportion of your first order to it. For a Western bridal range, a workable starting distribution is roughly 15% small (US 4–5.5), 45% medium (US 6–7.5), 30% large (US 8–9.5) and 10% extra large, with the extra-large portion largely made to order. Men's bands concentrate in the large and extra-large bands and should be planned separately.
Resizing and its limits
- Rings can usually be resized up or down by one to two sizes, depending on the setting and whether the band carries stones all the way around.
- Full-eternity bands cannot be resized without removing and resetting stones; specify accurately.
- Plated silver can be resized but the plating is compromised at the joint and needs re-plating.
- Titanium and tungsten cannot be resized at all — size them correctly the first time.
Chains, clasps and lengths
Chain length is quoted as the total wearable length including the clasp. If you are matching a pendant to a chain, remember that the pendant's bail adds 3–6 mm to where the pendant actually sits. For tennis bracelets and necklaces, specify the clasp type as well as the length: a double-locking box clasp with a safety catch is the minimum for a piece worn daily.