Please refer to the table below for approximate ring size comparisons. Many rings can also be resized.

Najo Size USA British Inside Circumference Inside Diameter
  3 E 1/2 43.5 mm 13.8 mm
  4 H 1/2 46.5 mm 15.0 mm
  5 J 1/2 49.0 mm 15.75 mm
X Small 6 L1/2 52.0 mm 16.5 mm
Small 7 N 1/2 55.0 mm 17.5 mm
Medium 8 P 1/2 57.0 mm 18.0 mm
Large 9 R 1/2 60.0 mm 19.0 mm
X Large 10 T 1/2 62.0 mm 22.0 mm


All rings come in a S, M and L. Limited styles are available in XS and XL. Type XS or XL in the search bar to view the full range in those sizes.