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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