Pipe Inch to Meter Conversion

Written by Matt Milbury on . Posted in Pipe

  • DN = Diametre Nominel - Diameter Nominal (metric)
    • Conform to International Standards Organization (ISO)
  • NPS = Nominal Pipe Size (inches)
    • 12" and below, the outside diameter (OD) was origionally set by the inside diameter (ID).
    • 14" and above, the outside diameter (OD) values are equal.
  • See Pipe Standards
Pipe Size DN (mm)Pipe Size NPS (in)

Pipe Size DN (mm) OD

Pipe Size NPS (in) OD
6 1/8 10.29 0.405
8 1/4  13.72  0.540
10 3/8  17.15  0.675
15 1/2  21.34  0.840
20 3/4  26.67  1.050
25 1  33.40  1.315
32 1 1/4  42.16  1.660
40 1 1/2  48.26  1.900
50 2  60.33  2.375
65 2 1/2  73.02  2.875
80 3  88.90  3.500
90 3 1/2  101.60  4.000
100 4  114.30 4.500
125 5 141.30 5.563
150 6  168.27  6.625
200 8  219.08  8.625
250 10 273.05  10.750
300 12  323.85 12.750
350 14  355.60 14.0
400 16  406.40  16.0
450 18  457.20  18.0
500 20  508.00  20.0
550 22  558.80  22.0
600 24  609.60  24.0
650 26  660.40  26.0
700 28  711.20  28.0
750 30  762.00  30.0
800 32  812.80  32.0
850 34 863.60 34.0
900 36  914.40 36.0
1000 40  1016.00  40.0
1050 42  1066.80  42.0
1100 44 1117.60 44.0
1150 46 1168.40 46.0
1200 48  1219.20  48.0
1300 52 1320.80 52.0
1400 54 1371.60  54.0
1500 60 1524.00  60.0
1600 64  1625.60  64.0
1800 72  1828.80  72.0
1900 76 1930.40 76.0
2000 80  2032.00  80.0
2200 88  2235.20  88.0
2300 92 2336.80 92.0