Step 1: Calibrate Your Screen

For Desktop: Place a standard credit/debit card inside the box below and make sure the top of the card touches the top of the dotted line. Use the slider below until the box fits the card exactly.
For Mobile: Place a debit or credit card on the top dotted line. Use the slider below until the bottom dotted line is just visible underneath the card.

Zoom: Next

Step 2: Match Your Ring

Put your ring on the screen and drag the circle until its outer red edge touches the inside diameter of your ring.

Adjust size:

Estimated size: –

For best results use a desktop or laptop screen.