1. Get a tape measure, a piece of string, or a strip of paper.
2. Wrap it around the finger where you’ll wear your ring. If you're planning a ring stack, think about where the ring will sit on your finger, and mark the point where the ends meet.
3. Place your string or paper strip on a flat surface and measure its length with a ruler up to the mark. Refer to the chart above to find the closest Tiffany ring size based on your measurement.