Coussin Éternel Diamond Ring

A considered fit

Have a ring that fits?

Use a round ring that fits the finger you are shopping for, on the same hand.

Have a standard credit or debit card, or a millimeter ruler, ready. No card details are needed.

Match your card or ruler

Choose your reference, then hold it gently against the screen. Look straight at the marks.

A ruler may be easier on a small screen.

Place your card flat in landscape orientation. Keep its bottom edge on the lower mark, then move the slider until the upper mark meets its top edge.

Slide to adjust. Use − / + to fine-tune.

Keep the reference clear of the controls. If you zoom, turn your device or change screens, set the screen scale again.

Check the other direction

Use the same reference for this second screen check.

Turn the card 90 degrees to portrait orientation. Keep its left edge on the left mark, then move the slider until the right mark meets its right edge.

Slide to adjust. Use − / + to fine-tune.

Your Estimated Ring Size

Your two readings agreed. This estimates your reference ring’s size; final fit also depends on the design and band width.

Your measurement is close to the boundary between two US sizes. Confirm the fit with an advisor before choosing.

Your reference ring is outside our US 4–13 guide. Contact an advisor for a suitable size.

Let us help you find the right fit

For a reliable fit, have the intended finger measured with a physical ring sizer. A jeweler can account for your knuckle and the chosen band width. You can also use our printable guides below.