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:

SImply Bo ring size chart guide in mm an inches for usa canda and uk

Inside Diameter MM (Measure a ring)

 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? Follow the steps below to measure your ring size at home:

  1. Tie a thin strap of paper around the finger you want to measure. Don’t tie it too tight. 
  2. Mark where the paper overlaps.
  3. Measure the length in mm with a ruler. The length of the paper corresponds to your size. 
  4. Use the size guide below to determine your ring size
    • 49mm = size 5
    • 52mm = size 6
    • 55mm= size 7
    • 57mm = size 8
    • 59mm = size 9
    • 62mm = size 10

Tip: When measuring your finger, your measurements need to be a 100% accurate as even a fraction of a millimeter can make a difference