To measure your ring size, you will need:

A ring

A bank card

This tool gives an estimate. For the most accurate result, use a ring that already fits the intended finger and match the circle to the inside edge of the ring.

How to measure your ring size at home

1. Take a ring that already fits the intended finger well.
2. Calibrate the screen: hold a bank card against the left edge of the screen (short side towards the screen) and move the slider until the outline matches the card when you look straight down.
3. Put the ring on the dark circle and adjust with + and − until the circle reaches the inside edge of the ring.
4. Tap Next — you’ll see your UA size along with US and EU.

Tip: don’t use browser zoom, and calibrate again if you switch devices. If in doubt between two sizes, choose the larger one.