How do you size a range before you have sales data?

A size return costs the outbound shipping, the return shipping, the repacking, and often the customer. It is worth thirty minutes of planning before the size run is fixed.

What size run should a first collection carry?

Five sizes is the practical minimum, seven is comfortable. Less than five and you will fail half your traffic; more than seven and the slow sizes sit as dead stock.

Start with the middle, track returns by size, and add the tails in the reorder. The tails are real demand, but they are small demand, and they tie up cash in the first order.

Why inner diameter beats letter sizes

A "size 7" is 17.3 mm inner diameter under the US system. A customer in Germany reading "size 7" may assume a European 7, which is roughly 15 mm and will not go on. Publishing the diameter in millimetres removes the ambiguity entirely and works in every market.

For a wide band — 6 mm or more — the same finger needs a slightly larger diameter, because the band covers more of the knuckle. This is why a chunky signet feels tighter than a 2 mm band in the same nominal size. If your range mixes widths, note it on the product page.

Bracelets and anklets

• Women's bracelets: 17–19 cm inner circumference covers the majority.
• Men's bracelets: 20–22 cm.
• Anklets: 23–25 cm, with an extender.

For chain bracelets an adjustable clasp or a 3 cm extender removes most sizing returns for a few cents per unit. On bangles, size is fixed and cannot be adjusted — which makes bangles a poor first category for a market you cannot measure.

What to put on the product page

One line of arithmetic and one image:

• Inner diameter in mm, plus the band width.
• A printable paper ring sizer, or a measurement instruction: wrap a strip of paper around the finger, mark, measure in mm, divide by 3.14.
• A note that wide bands run tight.

Sellers who publish diameter see fewer "too small" contacts than sellers who publish letters. It is not a design improvement, just an information one.

Sizing and production

Size range affects tooling for cast pieces, because a mould is made per size. For bands cut from tube, adding a size is a program change rather than a new mould, which is one more reason simple bands are the sensible first product. Tell us the size run at quotation stage; a range added later is a second tooling round.