Ring Size Conversion Chart

    
            US Size
            European Size [mm inner Circumference]
            German Size [mm internal diameter] 
        
            0 
            36.5
            11.6 
        
            37
             
             1/4
            37.2
            11.8 
        
             1/2
            37.8
            12 
        
            38
            12.1 
        
             3/4
            38.5
            12.2 
        
             39 
            
            1 
            39.1
            12.4 
        
            1 1/4
            39.7
            12.6 
        
            40
            12.7 
        
            1 3/4
            41
            13.1 
        
            2 
            41.7
            13.3 
        
            42
            13.4 
        
            2 1/4
            42.3
            13.5 
        
            2 1/2
            42.9
            13.7 
        
            43
            
            2 3/4
            43.6
            13.9 
        
            44
            14 
        
            3 
            44.2
            14.1 
        
            3 1/4
            44.8
            14.3 
        
            45
            
            3 1/2
            45.5
            14.5 
        
            46
            14.6 
        
            3 3/4
            46.1
            14.7 
        
            4 
            46.8
            14.9 
        
            47
            15 
        
            4 1/4
            47.4
            15.1 
        
            4 1/2
            48
            15.3 
        
            4 3/4
            48.7
            15.5 
        
            49
            15.6 
        
            5 
            49.3
            15.7 
        
            5 1/4
            50
            15.9 
        
            5 1/2
            50.6
            16.1 
        
            51
            16.2 
        
            5 3/4
            51.2
            16.3 
        
            6 
            51.9
            16.5 
        
            52
            16.6 
        
            6 1/4
            52.5
            16.7 
        
            53
            16.9 
        
            6 1/2
            53.1
            16.9 
        
            53.5
            17 
        
            6 3/4
            53.8
            17.1 
        
            54
            17.2 
        
            7 
            54.4
            17.3 
        
            55
            
            7 1/4
            55.1
            17.5 
        
            7 1/2
            55.7
            17.7 
        
            56
            17.8 
        
            7 3/4
            56.3
            17.9 
        
            56.5
            18 
        
            8 
            57
            18.1 
        
            8 1/4
            57.6
            18.3 
        
            58
            
            8 1/2
            58.3
            18.5 
        
            8 3/4
            58.9
            18.7 
        
            59
            18.8 
        
            9 
            59.5
            18.9 
        
            9 1/4
            60
            19.1 
        
            9 1/2
            60.8
            19.4 
        
            61
            
            9 3/4
            61.4
            19.6 
        
            62
            19.7 
        
            10 
            62.1
            19.8 
        
            10 1/4
            62.7
            20 
        
            63
            20.1 
        
            10 1/2
            63.4
            20.2 
        
            10 3/4
            64
            20.4 
        
            11 
            64.6
            20.6 
        
            65
            20.7 
        
            11 1/4
            65.3
            20.8 
        
            11 1/2
            65.9
            21 
        
            66
            
            11 3/4
            66.6
            21.2 
        
            67
            21.3 
        
            12 
            67.2
            21.4