Ring Size Guide
If you already have your accurate finger measurement or already know your ring size but just need to convert it to another country’s size, use our ring size conversion chart table in MM or Inches for different countries:

Inside Diameter MM | Inside Diameter Inches | USA & Canada Ring Size | UK, Ireland, Australia & New Zealand Ring Size |
15 mm | 0.59 | 4 | H |
15.3 mm | 0.60 | 4.5 | I |
15.6 mm | 0.62 | 5 | J |
16.2 mm | 0.63 | 5.5 | K |
16.5 mm | 0.65 | 6 | L |
16.9 mm | 0.67 | 6.5 | M |
17.3 mm | 0.68 | 7 | N |
17.8 mm | 0.70 | 7.5 | O |
18.2 mm | 0.71 | 8 | P |
18.5 mm | 0.73 | 8.5 | Q |
19.0 mm | 0.75 | 9 | R |
19.4 mm | 0.76 | 9.5 | S |
19.9 mm | 0.78 | 10 | T |
20.4 mm | 0.79 | 10.5 | U |
20.6 mm | 0.81 | 11 | V |
21.0 mm | 0.83 | 11.5 | W |
21.6 mm | 0.84 | 12 | X |
22.0 mm | 0.86 | 12.5 | Y |
22.3 mm | 0.87 | 13 | Z |
22.9 mm | 0.89 | 13.5 | Z+2 |
23.2 mm | 0.91 | 14 | Z+3 |
23.6 mm | 0.92 | 14.5 | Z+4 |
24.0 mm | 0.94 | 15 | Z+5 |
Don't know your ring size? Here are a few options for finding out which size to choose:
Option 1
Tie a thread around the finger you want to measure. Don’t tie it too tight. Then measure the length of the thread in mm. The length of the thread corresponds to your size. Round off according to the table.
Option 2
Use a ring that fits and measure its inner measure using a measuring tape or a ring mandrel. Round off according to the table.
Tip: When measuring your finger, your measurements need to be a 100% accurate as even a fraction of a millimeter can make a difference