Sizing Guide

Find Your Perfect Fit with DimaDiam

Measure an Existing Ring

Already have a ring that fits perfectly? Here's how to measure it:

  1. Choose a ring that fits the finger you intend to wear your new piece on.

  2. Measure the internal diameter (inside edge to inside edge) of the ring in millimeters (mm).

  3. Use the chart below to find your size.

Internal Diameter (mm) US/Canada Size UK/Australia Size German Ring Size
14.1 mm 3 F 14
14.9 mm 4 H 15
15.7 mm 5 J 15 ¾
16.5 mm 6 L 16 ½
17.3 mm 7 N 17 ¼
18.1 mm 8 P 18
19.0 mm 9 R 19
19.8 mm 10 T 20
20.6 mm 11 V 20 ¾
21.4 mm 12 X 21 ¼
22.2 mm 13 Z 22

Measure Your Finger

No ring? No problem! Here's how to measure your finger directly:

  1. Wrap a strip of paper around the base of your finger where you want the ring to sit.

  2. Pull the paper snug (tight, but not uncomfortable) to get the best fit.

  3. Mark where the ends meet.

  4. Measure the length (in millimeters) with a ruler.

  5. Match your measurement with the chart below.

Circumference (mm) US/Canada Size UK/Australia Size German Ring Size
44.2 mm 3 F 14
46.8 mm 4 H 15
49.3 mm 5 J 15 ¾
51.9 mm 6 L 16 ½
54.4 mm 7 N 17 ¼
57 mm 8 P 18
59.5 mm 9 R 19
62.1 mm 10 T 20
64.6 mm 11 V 20 ¾
67.2 mm 12 X 21 ¼
67.7 mm 13 Z 22

Tips & Tricks for Accurate Sizing

  • Measure your finger at the end of the day, when it’s naturally a little larger.

  • Cold weather can make fingers shrink slightly — make sure your hands are warm.

  • Avoid measuring after drinking alcohol or eating salty foods — both can cause temporary swelling.