A Schedule 80 size chart shows the relationship between Nominal Pipe Size (NPS), outside diameter (OD), and wall thickness for Schedule 80 steel pipe. Unlike tubing dimensions, pipe size is normally identified by NPS, while the actual outside diameter remains standardized for each nominal size.
All data in the table below is derived from ASME B36.10M and applies to carbon steel and seamless steel pipes; in the event of any discrepancy, the dimensions specified in the standard document shall prevail. Please contact ALLLAND for further details.
Schedule 80 Steel Pipe Size Chart
| NPS | DN | Outside Diameter (OD) | Schedule | Wall Thickness |
| 1/2″ | DN15 | 21.3 mm | SCH 80 | 3.73 mm |
| 3/4″ | DN20 | 26.7 mm | SCH 80 | 3.91 mm |
| 1″ | DN25 | 33.4 mm | SCH 80 | 4.55 mm |
| 1-1/4″ | DN32 | 42.2 mm | SCH 80 | 4.85 mm |
| 1-1/2″ | DN40 | 48.3 mm | SCH 80 | 5.08 mm |
| 2″ | DN50 | 60.3 mm | SCH 80 | 5.54 mm |
| 2-1/2″ | DN65 | 73.0 mm | SCH 80 | 7.01 mm |
| 3″ | DN80 | 88.9 mm | SCH 80 | 7.62 mm |
| 4″ | DN100 | 114.3 mm | SCH 80 | 8.56 mm |
| 5″ | DN125 | 141.3 mm | SCH 80 | 9.53 mm |
| 6″ | DN150 | 168.3 mm | SCH 80 | 10.97 mm |
| 8″ | DN200 | 219.1 mm | SCH 80 | 12.70 mm |
| 10″ | DN250 | 273.1 mm | SCH 80 | 15.09 mm |
| 12″ | DN300 | 323.9 mm | SCH 80 | 17.45 mm |
| 14″ | DN350 | 355.6 mm | SCH 80 | 19.05 mm |
| 16″ | DN400 | 406.4 mm | SCH 80 | 21.44 mm |
| 18″ | DN450 | 457.2 mm | SCH 80 | 23.83 mm |
| 20″ | DN500 | 508.0 mm | SCH 80 | 26.19 mm |
| 24″ | DN600 | 610.0 mm | SCH 80 | 30.96 mm |
Schedule 80 Pipe Inside Diameter Size Chart
| NPS | OD | SCH 80 WT | Approx. ID |
| 1/2″ | 21.3 | 3.73 | 13.84 |
| 1″ | 33.4 | 4.55 | 24.3 |
| 2″ | 60.3 | 5.54 | 49.22 |
| 3″ | 88.9 | 7.62 | 73.66 |
| 4″ | 114.3 | 8.56 | 97.18 |
| 6″ | 168.3 | 10.97 | 146.36 |
| 8″ | 219.1 | 12.7 | 193.7 |
| 10″ | 273.1 | 15.09 | 242.92 |
| 12″ | 323.9 | 17.45 | 288.99 |
The calculation formula used is: ID = OD − 2 × WT.
