Jewelers Reference
Standard US Ring Sizes

US
0000

00

0

1/2 

3/4 



1 1/4

1 1/2

1 3/4



2 1/4

2 1/2

2 3/4



3 1/4

3 1/2

3 3/4



4 1/4

4 1/2

4 3/4



5 1/4

5 1/2

5 3/4



6 1/4

DIAMETER IN INCHES
DIAMETER IN MM

US
DIAMETER IN INCHES
DIAMETER IN MM
0.390

0.422

0.454

0.474

0.482

0.487

0.496

0.503

0.511

0.520

0.528

0.536

0.544

0.553

0.561

0.569

0.577

0.585

0.592

0.601

0.611

0.618

0.626

0.634

0.642

0.650

0.658

9.91

10.72

11.53

11.95

12.18

12.37

12.60

12.78

13.00

13.21

13.41

13.61

13.83

14.05

14.25

14.45

14.65

14.86

15.04

15.27

15.53

15.70

15.90

16.10

16.30

16.51

16.71

 1/2

6 3/4



7 1/4

7 1/2

7 3/4



8 1/4

8 1/2

8 3/4



9 1/4

9 1/2

9 3/4

10 

10 1/4

10 1/2

10 3/4

11 

11 1/4

11 1/2

11 3/4

12 

12 1/4

12 1/2

12 3/4

13 

0.666

0.674

0.683

0.687

0.699

0.707

0.716

0.722

0.732

0.736

0.748

0.757

0.764

0.772

0.781

0.788

0.797

0.805

0.814

0.821

0.830

0.836

0.846

0.854

0.862

0.870

0.879

16.92

17.13

17.35

17.45

17.75

17.97

18.19

18.35

18.53

18.69

18.89

19.22

19.41

19.62

19.84

20.02

20.20

20.44

20.68

20.85

21.08

21.24

21.49

21.69

21.89

22.10

22.33

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