How to Find Your Ring Size

The best way to find your ring size is to measure a ring you already own that fits well.

Method 1: Measure an Existing Ring

  1. Find a ring that fits the finger you want to wear your new ring on
  2. Measure the inside diameter of the ring in millimeters with a ruler
  3. Use the chart below to find your US size

Method 2: Measure Your Finger

  1. Cut a thin strip of paper about 6 inches long
  2. Wrap it snugly around your finger where you'd wear the ring
  3. Mark where the paper overlaps
  4. Measure the length in millimeters
  5. Match the circumference (L) to the chart below

Ring Size Chart

Quick Reference

US Size Diameter (mm) Circumference (mm)
5 15.7 49.3
5.5 16.1 50.6
6 16.5 51.9
6.5 16.9 53.2
7 17.4 54.5
7.5 17.8 55.8
8 18.2 57.1
8.5 18.6 58.4
9 18.9 59.7
9.5 19.4 60.1
10 19.8 62.2
10.5 20.3 63.5
11 20.7 64.8
11.5 21.1 66.2
12 21.5 67.4
12.5 21.9 68.7
13 22.3 70.0
13.5 22.7 71.3
14 23.1 72.6
14.5 23.5 73.9
15 24.0 75.2
15.5 24.4 76.5
16 24.8 77.8

Tips for Accurate Sizing

Measure at the end of the day. Fingers swell slightly throughout the day, so evening measurements are most accurate.

Measure when you're warm. Cold fingers are smaller. Take your measurement when your hands are at room temperature.

Between sizes? Size up. It's easier to wear a slightly loose ring than one that's too tight.

Consider the band width. Wider bands fit more snugly than thin bands. If you're buying a wide band, you might want to go up half a size.

Free Resizing

If your ring doesn't fit perfectly, we offer free resizing within 7 days of receiving your order. Just contact us at contact@casaisajewelry.com, and Catherine will take care of it.

Need Help?

Unsure about your size? Email us at contact@casaisajewelry.com, and Catherine will help you figure it out!