Conversion Table: DN ↔ Inches

Written By: Gustav Svendsen
November 10, 2025
DN (Diameter Nominal) ↔ NPS (Nominal Pipe Size)
DN (Millimeters) NPS (Inches)
6 1/8
8 1/4
10 3/8
15 1/2
20 3/4
25 1
32 1 1/4
40 1 1/2
50 2
65 2 1/2
80 3
90 3 1/2
100 4
115 4 1/2
125 5
150 6
200 8
250 10
300 12
350 14
400 16
450 18
500 20
600 24
700 28
800 32
900 36
1000 40

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