Ring Size Finder

Place a ring that fits you on the screen, or enter your finger circumference, to get its US, UK, European, Japanese and Korean ring size before you order a ring online.

How to use

1. "Place a ring on the screen" works only after you press "Calibrate screen" and calibrate the screen.
2. Lay the ring against the left and bottom guide lines and adjust until the yellow circle exactly fills the inside of the ring.
3. Without a ring, choose "Enter finger circumference" and type the circumference in mm measured with a paper strip or a thread.
4. The table shows the "Nearest" size in each system, with one size down and one size up. The "Size conversion table" lists all sizes.

How it works

• Every size is calculated from the inside circumference (inside diameter × π). The European size (ISO 8653) is that circumference in mm; US sizes use inside diameter = 11.63 mm + 0.8128 mm × size.
• Korean sizes follow a trade chart, not a national standard: size 1 is 44 mm around, plus 1 mm per size. Sellers can differ, so compare the millimetre values with the seller's chart.
• A difference of 0.3 mm in diameter is one Korean size or about half a US size, so treat the neighboring sizes as candidates.

Questions and answers

How can I measure my ring size at home?

Wrap a paper strip 3 to 5 mm wide, or a thread, once around the finger, mark the overlap, and measure it flat. Enter that length as the "Finger circumference".

What ring size is a 55 mm finger circumference?

In Europe the size is 55, and by the Korean trade chart it is 12. In the US it is about size 7, because 55 mm ÷ π is 17.5 mm inside diameter.

Should I choose a bigger size for a wide band?

A wide band feels tighter than a narrow one of the same size, so people usually go up about half a size. For an expensive ring, have it checked with a ring gauge in a shop.