Pipe Schedule Chart (ASME B36.10 & B36.19)
This pipe schedule chart gives the outside diameter, wall thickness and theoretical weight per metre of steel pipe from ½" to 24" NPS (DN 15 to DN 600) in the most used schedules. Wall thicknesses for Schedule 5S and 10S are from ASME B36.19M, which covers stainless steel pipe, and those for Schedule 40, 80, 160 and XXS are from ASME B36.10M, which covers welded and seamless wrought steel pipe.
How to read a pipe schedule
Pipe is identified by its nominal pipe size (NPS) in inches or its nominal diameter (DN) in millimetres, and by its schedule, which sets the wall thickness. For each NPS the outside diameter is fixed, so a higher schedule means a thicker wall and a smaller bore. From NPS 14 upward, the NPS equals the outside diameter in inches; below that, the outside diameter is larger than the nominal size – for example, 2" NPS pipe has an outside diameter of 60.3 mm.
The "S" schedules (5S, 10S, 40S, 80S) are used for stainless steel pipe to ASME B36.19M. Schedule 40S and 40 have the same wall thickness up to NPS 10, and 80S and 80 are the same up to NPS 8; at larger sizes the S schedules are thinner. Carbon steel pipe is also described by weight class: STD (standard), XS (extra strong) and XXS (double extra strong). STD equals Schedule 40 up to NPS 10, and XS equals Schedule 80 up to NPS 8.
Outside diameter and wall thickness
| NPS, inch | DN | OD, mm | Sch 5S | Sch 10S | Sch 40 | Sch 80 | Sch 160 | Sch XXS |
|---|---|---|---|---|---|---|---|---|
| ½ | 15 | 21.3 | 1.65 | 2.11 | 2.77 | 3.73 | 4.78 | 7.47 |
| ¾ | 20 | 26.7 | 1.65 | 2.11 | 2.87 | 3.91 | 5.56 | 7.82 |
| 1 | 25 | 33.4 | 1.65 | 2.77 | 3.38 | 4.55 | 6.35 | 9.09 |
| 1¼ | 32 | 42.2 | 1.65 | 2.77 | 3.56 | 4.85 | 6.35 | 9.70 |
| 1½ | 40 | 48.3 | 1.65 | 2.77 | 3.68 | 5.08 | 7.14 | 10.15 |
| 2 | 50 | 60.3 | 1.65 | 2.77 | 3.91 | 5.54 | 8.74 | 11.07 |
| 2½ | 65 | 73.0 | 2.11 | 3.05 | 5.16 | 7.01 | 9.53 | 14.02 |
| 3 | 80 | 88.9 | 2.11 | 3.05 | 5.49 | 7.62 | 11.13 | 15.24 |
| 4 | 100 | 114.3 | 2.11 | 3.05 | 6.02 | 8.56 | 13.49 | 17.12 |
| 5 | 125 | 141.3 | 2.77 | 3.40 | 6.55 | 9.53 | 15.88 | 19.05 |
| 6 | 150 | 168.3 | 2.77 | 3.40 | 7.11 | 10.97 | 18.26 | 21.95 |
| 8 | 200 | 219.1 | 2.77 | 3.76 | 8.18 | 12.70 | 23.01 | 22.23 |
| 10 | 250 | 273.1 | 3.40 | 4.19 | 9.27 | 15.09 | 28.58 | 25.40 |
| 12 | 300 | 323.9 | 3.96 | 4.57 | 10.31 | 17.48 | 33.32 | 25.40 |
| 14 | 350 | 355.6 | 3.96 | 4.78 | 11.13 | 19.05 | 35.71 | – |
| 16 | 400 | 406.4 | 4.19 | 4.78 | 12.70 | 21.44 | 40.49 | – |
| 18 | 450 | 457.0 | 4.19 | 4.78 | 14.27 | 23.83 | 45.24 | – |
| 20 | 500 | 508.0 | 4.78 | 5.54 | 15.09 | 26.19 | 50.01 | – |
| 24 | 600 | 610.0 | 5.54 | 6.35 | 17.48 | 30.96 | 59.54 | – |
A dash means the schedule is not listed for that size. Other schedules – 10, 20, 30, 60, 100, 120 and 140 – and the STD and XS weight classes are given in ASME B36.10M.
Weight per metre
Weights are calculated as (OD − WT) × WT × 0.02466 kg/m, which is the plain-end weight of carbon steel pipe. For austenitic stainless steel, multiply by about 1.01–1.02, as its density is slightly higher. For other sizes and materials, use our weight calculator.
| NPS, inch | OD, mm | Sch 5S | Sch 10S | Sch 40 | Sch 80 | Sch 160 | Sch XXS |
|---|---|---|---|---|---|---|---|
| ½ | 21.3 | 0.80 | 1.00 | 1.27 | 1.62 | 1.95 | 2.55 |
| ¾ | 26.7 | 1.02 | 1.28 | 1.69 | 2.20 | 2.90 | 3.64 |
| 1 | 33.4 | 1.29 | 2.09 | 2.50 | 3.24 | 4.24 | 5.45 |
| 1¼ | 42.2 | 1.65 | 2.69 | 3.39 | 4.47 | 5.61 | 7.77 |
| 1½ | 48.3 | 1.90 | 3.11 | 4.05 | 5.41 | 7.25 | 9.55 |
| 2 | 60.3 | 2.39 | 3.93 | 5.44 | 7.48 | 11.11 | 13.44 |
| 2½ | 73.0 | 3.69 | 5.26 | 8.63 | 11.41 | 14.92 | 20.39 |
| 3 | 88.9 | 4.52 | 6.46 | 11.29 | 15.27 | 21.35 | 27.68 |
| 4 | 114.3 | 5.84 | 8.37 | 16.08 | 22.32 | 33.54 | 41.03 |
| 5 | 141.3 | 9.46 | 11.56 | 21.77 | 30.97 | 49.12 | 57.43 |
| 6 | 168.3 | 11.31 | 13.83 | 28.26 | 42.56 | 67.57 | 79.22 |
| 8 | 219.1 | 14.78 | 19.97 | 42.55 | 64.64 | 111.27 | 107.93 |
| 10 | 273.1 | 22.61 | 27.79 | 60.31 | 96.02 | 172.34 | 155.16 |
| 12 | 323.9 | 31.25 | 35.99 | 79.73 | 132.09 | 238.78 | 186.98 |
| 14 | 355.6 | 34.34 | 41.36 | 94.55 | 158.11 | 281.72 | – |
| 16 | 406.4 | 41.56 | 47.34 | 123.31 | 203.54 | 365.38 | – |
| 18 | 457.0 | 46.79 | 53.31 | 155.81 | 254.57 | 459.39 | – |
| 20 | 508.0 | 59.32 | 68.65 | 183.43 | 311.19 | 564.85 | – |
| 24 | 610.0 | 82.58 | 94.53 | 255.43 | 442.11 | 808.27 | – |
Choosing a schedule
The required wall thickness is calculated from the design pressure, temperature, material allowable stress, corrosion allowance and mill tolerance, using the piping code for the project, such as ASME B31.3 for process piping. The next standard schedule at or above the calculated thickness is then selected. Thin-wall Schedule 10S is common for stainless steel water and utility lines, Schedule 40 for general process piping, and Schedule 80 and heavier for high-pressure lines, small-bore connections and threaded pipe.
Pipe in all these schedules is available in seamless and welded construction – see seamless pipes and tubes, welded pipes and tubes, stainless steel seamless pipes, carbon steel seamless pipes and ASTM A106 Grade B pipes. More charts are on the technical resources page.
The values in this chart are nominal dimensions for guidance. For design and purchasing, always refer to the current edition of the standard and the project specification.
Frequently Asked Questions
A pipe schedule is a number that sets the wall thickness of a pipe for a given nominal size. For the same NPS, the outside diameter stays the same and a higher schedule means a thicker wall.
Schedule 80 pipe has a thicker wall than Schedule 40 of the same size, so it has a smaller bore, weighs more and is rated for higher pressure. For 2" NPS, Schedule 40 is 3.91 mm and Schedule 80 is 5.54 mm.
Schedule 40S is from ASME B36.19M for stainless steel pipe. It has the same wall thickness as Schedule 40 up to NPS 10 but is thinner for NPS 12 and above.
ASME B36.10M covers welded and seamless wrought steel pipe, and ASME B36.19M covers stainless steel pipe. Both give outside diameters, wall thicknesses and weights for each schedule.
For carbon steel, weight in kg/m = (OD − WT) × WT × 0.02466, with OD and WT in millimetres. For stainless steel, multiply the result by about 1.01–1.02.