Ring Size Guide — Cassienne

1

Measure a ring you wear

Lay a ring that fits the same finger on a ruler and measure straight across the inside, edge to edge, in millimetres. Find that number in the inside diameter column below.

2

Wrap a strip around your finger

Wrap a thin strip of paper or a piece of string around the base of your finger, mark where it meets, then measure the length in millimetres. Find it in the circumference column.

3

Print our ring sizer

Circles to match a ring you own, and a strip to wrap around your finger — printed at actual size.

Size Chart

US, UK, EU & Indian Sizes

Our rings are made in US sizes. Other systems are the closest equivalents.

US & Canada	Inside diameter	Circumference	UK & Australia	EU	India

Getting it right

Measure at the end of the day. Fingers are slightly larger in the evening and when warm; cold hands give a size too small.
Mind the knuckle. The ring has to slide over it. If your knuckle is noticeably wider than the base of your finger, choose a size between the two measurements.
Wide bands fit snugger. For bands 6 mm or wider, go up half a size.
Between two sizes? Choose the larger one.
Buying a surprise? Borrow a ring they wear on that finger and measure it, or ask a close friend.

Still unsure? Send us a photo of your measurement and we'll help you choose.

Message Us Contact the Concierge

Cassienne · Printable Ring Sizer Print at 100% / Actual size — not "Fit to page".

Check first: hold a real ruler against the printed ruler below. If 0–50 mm don't match exactly, change the print scale to 100% and print again.

Circles — place a ring you own on top

The right size is the circle whose line sits exactly along the inside edge of your ring. Between two? Choose the larger.

Ruler — for a paper strip or string

Wrap a thin paper strip or string around the base of your finger, mark where it meets, lay it from 0 and read the length. Then find the closest circumference below.

On screen this preview isn't to scale — print it.