Comparison for DN, NPS, OD

1. NPS is short for nominal pipe size, which is based on inches and a schedule (Sched. or Sch.). The term NB (nominal bore) is frequently used interchangeably with NPS.
2. DN is short for nominal diameter, which is measured in millimeters.
3. OD is short for outside diameter, which is measured in millimeters.

 
Nominal
pipesize
Outside
Diameter
Nominal Wall
Thickness
NPS DN OD SCH 5s SCH lOs SGH 10 SCH 20 SCH 30 SCH 40s STD SCH 40 SCH 60 SCH 80s XS SCH 80 SCH 10O SCH 20 SCH 140 SCH 160 XXS
   
1/8 6 10.3   1.24       1.73 1.73 1.73   2.41 2.41 2.41          
1/4 8 13.7   1.65       2.24 2.24 2.24   3.02 3.02 3.02          
3/8 10 17.1   1.65       2.31 2,31 2.31   3.20 3.20 3.20          
1/2 15 21.3 1.65 2.11       2.77 2.77 2.77   3.73 3.73 3.73       4.78 7.47
3/4 20 26.7 1.65 2.11       2.87 2.87 2.87   3.91 3.91 3.91       5.56 7.82
1 25 33.4 1.65 2.77       3.38 3.38 3.38   4.55 4.55 4.55       6.35 9.09
1l/4 32 42.2 1.65 2.77       3.56 3.56 3,56   4.85 4.85 4.85       6.35 9.7
11/2 40 48.3 1.65 2.77       3.68 3.68 3.68   5.08 5.08 5.08       7.14 10.15
2 50 60.3 1.65 2.77       3.91 3.91 3,9n   5.54 5.54 5.54       8.74 11.07
21/2 65 73.0 2.11 3.05       5.16 5.16 5.16   7.01 7.01 7.01       9.53 14.02
3 80 88.9 2.11 3.05       5.49 5.49 5.49   7.62 7.62 7.62       11.13 15.24
31/2 90 101.6 2.11 3.05       5.74 5.74 5.74   8.08 8.08 8.08          
4 100 114.3 2.11 3.05       6.02 6.02 6.02   8.56 8,56 8.56   11.13   13.49 17.12
5 125 141.3 2.77 3.40       6.55 6.55 6.55   9.53 9,53 9.53   12.70   15.88 19.05
6 150 168.3 2.77 3.40       7.11 7.11 7.11   1O.97 1O.97 10.97   14.27   18.26 21.95
8 200 219.1 2.77 3.76   6.35 7.04 8.18 8.18 8.18 10.31 12.70 12.70 12.70 15.09 18.26 20.62 23.01 22.23
1O 250 273.1 3.40 4.19   6.35 7.80 9.27 9.27 9.27 12.70 12.70 12.70 15.09 18.26 21.44 25.40 28.58 25.40
12 300 323.9 3.96 4.57   6.35 8.38 9.53 9.53 1O.31 14.27 12.70 12.70 17.48 21.44 25.40 28.58 33.32 25.40
14 350 355.6 3.96 4.78 6.35 7.92 9.53   9.53 11.13 15.09   12.70 19.05 23.83 27.79 31.75 35.71  
16 400 406.4 4.19 4.78 6.35 7.92 9.53   9.53 12.70 i6.66   12.70 21.44 26.19 30.96 36.53 40.49  
18 450 457.2 4.19 4.78 6.35 7.92 11.13   9.53 14.27 19.05   12.70 23.83 29.36 34.93 39,67 45.24  
2O 500 508 4.78 5.54 6.35 9.53 12.70   9.53 15.09 20.62   12.70 26.19 32.54 38.10 44.45 50.01  
22   559 4.78 5.54 6.35 9.53 12.70   9.53   22.23   12.70 28.58 34.93 41.28 47.63 53.98  
24 600 610 5.54 6.35 6.35 9.53 14.27   9.53 17.48 24.61   12.70 30.96 38.89 46.02 52.37 59.54  
26   660     7.92 12.70     9.53       12.70            
28 700 711     7.92 12.70 15.88   9.53       12.70            
3O   762 6.35 7.92 7.92 12.70 15.88   9.53       12.70            
32 800 813     7.92 12.70 15.88   9.53 17.48     12.70            
34   884     7.92 12.70 15.88   9.53 17.48     12.70            
36 900 914     7.92 12.70 15.88   9.53 19.05     12.70            
38   965             9.53       12.70            
40 1000 1016           9.53   12.70                  
42   1067             9.53       12.70            
44 1100 1118             9.53       12.70            
46   1168             9.53       12.70            
48 1200 1219             9.53     12.70              
52   1321                                  
56 1422                                    
6O 1524                                    
64 1600 1626                                  
68   1727                                  
72 1800 1829                                  
76   1930                                  
8O 2000 2032