Ring size calculator
Ring size calculator.
Measure round your finger with a strip of paper, or across the inside of a ring that fits, and enter the number in millimetres. Nothing you type leaves this page.
How it works
US sizes follow the common rule: the inside diameter is 11.63 mm plus 0.8128 mm for every size. EU sizes (ISO 8653) are simply the inside circumference in millimetres. UK sizes are letters, one letter for every half US size; charts differ a little between makers, so treat them as a guide. For a wide band, between two sizes, choose the larger.
Before you measure
- Measure the finger, and the hand, you will wear the ring on.
- Measure in the afternoon or evening, when fingers are a little larger, and not with cold hands.
- Make sure the ring will pass over your knuckle.
Step by step, with a size table: how to find your ring size at home. Lychnos Ring is planned in US sizes 6 to 13; if you are not sure, you will be able to choose “not sure yet” when pre-orders open.
Questions
How do I measure my finger in millimetres?
Wrap a thin strip of paper round the base of the finger, snug but not tight, mark where it overlaps, and measure the length with a ruler. That is the circumference.
I am between two sizes. Which one?
For a wide band, such as a smart ring, the larger size is usually more comfortable. The calculator suggests the larger one for Lychnos Ring.