Steel Pipe Schedule Chart
Every size from NPS 1/8″ to 48″, every schedule, in mm or inch. Tap any wall thickness for the bore and weight per metre.
36 sizes · 17 schedules
| Pipe size | Nominal wall thickness by schedule | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NPS | DN | OD | 5S | 10S | 10 | 20 | 30 | 40S | STD | 40 | 60 | 80S | XS | 80 | 100 | 120 | 140 | 160 | XXS |
| 1/8″ | 6 | 10.3 | 1.24 | 1.73 | 1.73 | 1.73 | 2.41 | 2.41 | 2.41 | ||||||||||
| 1/4″ | 8 | 13.7 | 1.65 | 2.24 | 2.24 | 2.24 | 3.02 | 3.02 | 3.02 | ||||||||||
| 3/8″ | 10 | 17.1 | 1.65 | 2.31 | 2.31 | 2.31 | 3.20 | 3.20 | 3.20 | ||||||||||
| 1/2″ | 15 | 21.3 | 1.65 | 2.11 | 2.77 | 2.77 | 2.77 | 3.73 | 3.73 | 3.73 | 4.78 | 7.47 | |||||||
| 3/4″ | 20 | 26.7 | 1.65 | 2.11 | 2.87 | 2.87 | 2.87 | 3.91 | 3.91 | 3.91 | 5.56 | 7.82 | |||||||
| 1″ | 25 | 33.4 | 1.65 | 2.77 | 3.38 | 3.38 | 3.38 | 4.55 | 4.55 | 4.55 | 6.35 | 9.09 | |||||||
| 1 1/4″ | 32 | 42.2 | 1.65 | 2.77 | 3.56 | 3.56 | 3.56 | 4.85 | 4.85 | 4.85 | 6.35 | 9.70 | |||||||
| 1 1/2″ | 40 | 48.3 | 1.65 | 2.77 | 3.68 | 3.68 | 3.68 | 5.08 | 5.08 | 5.08 | 7.14 | 10.15 | |||||||
| 2″ | 50 | 60.3 | 1.65 | 2.77 | 3.91 | 3.91 | 3.91 | 5.54 | 5.54 | 5.54 | 8.74 | 11.07 | |||||||
| 2 1/2″ | 65 | 73.0 | 2.11 | 3.05 | 5.16 | 5.16 | 5.16 | 7.01 | 7.01 | 7.01 | 9.53 | 14.02 | |||||||
| 3″ | 80 | 88.9 | 2.11 | 3.05 | 5.49 | 5.49 | 5.49 | 7.62 | 7.62 | 7.62 | 11.13 | 15.24 | |||||||
| 3 1/2″ | 90 | 101.6 | 2.11 | 3.05 | 5.74 | 5.74 | 5.74 | 8.08 | 8.08 | 8.08 | |||||||||
| 4″ | 100 | 114.3 | 2.11 | 3.05 | 6.02 | 6.02 | 6.02 | 8.56 | 8.56 | 8.56 | 11.13 | 13.49 | 17.12 | ||||||
| 5″ | 125 | 141.3 | 2.77 | 3.40 | 6.55 | 6.55 | 6.55 | 9.53 | 9.53 | 9.53 | 12.70 | 15.88 | 19.05 | ||||||
| 6″ | 150 | 168.3 | 2.77 | 3.40 | 7.11 | 7.11 | 7.11 | 10.97 | 10.97 | 10.97 | 14.27 | 18.26 | 21.95 | ||||||
| 8″ | 200 | 219.1 | 2.77 | 3.76 | 6.35 | 7.04 | 8.18 | 8.18 | 8.18 | 10.31 | 12.70 | 12.70 | 12.70 | 15.09 | 18.26 | 20.62 | 23.01 | 22.23 | |
| 10″ | 250 | 273.1 | 3.40 | 4.19 | 6.35 | 7.80 | 9.27 | 9.27 | 9.27 | 12.70 | 12.70 | 12.70 | 15.09 | 18.26 | 21.44 | 25.40 | 28.58 | 25.40 | |
| 12″ | 300 | 323.9 | 3.96 | 4.57 | 6.35 | 8.38 | 9.53 | 9.53 | 10.31 | 14.27 | 12.70 | 12.70 | 17.48 | 21.44 | 25.40 | 28.58 | 33.32 | 25.40 | |
| 14″ | 350 | 355.6 | 3.96 | 4.78 | 6.35 | 7.92 | 9.53 | 9.53 | 11.13 | 15.09 | 12.70 | 19.05 | 23.83 | 27.79 | 31.75 | 35.71 | |||
| 16″ | 400 | 406.4 | 4.19 | 4.78 | 6.35 | 7.92 | 9.53 | 9.53 | 12.70 | 16.66 | 12.70 | 21.44 | 26.19 | 30.96 | 36.53 | 40.49 | |||
| 18″ | 450 | 457.2 | 4.19 | 4.78 | 6.35 | 7.92 | 11.13 | 9.53 | 14.27 | 19.05 | 12.70 | 23.83 | 29.36 | 34.93 | 39.67 | 45.24 | |||
| 20″ | 500 | 508.0 | 4.78 | 5.54 | 6.35 | 9.53 | 12.70 | 9.53 | 15.09 | 20.62 | 12.70 | 26.19 | 32.54 | 38.10 | 44.45 | 50.01 | |||
| 22″ | 550 | 559.0 | 4.78 | 5.54 | 6.35 | 9.53 | 12.70 | 9.53 | 22.23 | 12.70 | 28.58 | 34.93 | 41.28 | 47.63 | 53.98 | ||||
| 24″ | 600 | 610.0 | 5.54 | 6.35 | 6.35 | 9.53 | 14.27 | 9.53 | 17.48 | 24.61 | 12.70 | 30.96 | 38.89 | 46.02 | 52.37 | 59.54 | |||
| 26″ | 650 | 660.0 | 7.92 | 12.70 | 9.53 | 12.70 | |||||||||||||
| 28″ | 700 | 711.0 | 7.92 | 12.70 | 15.88 | 9.53 | 12.70 | ||||||||||||
| 30″ | 750 | 762.0 | 6.35 | 7.92 | 7.92 | 12.70 | 15.88 | 9.53 | 12.70 | ||||||||||
| 32″ | 800 | 813.0 | 7.92 | 12.70 | 15.88 | 9.53 | 17.48 | 12.70 | |||||||||||
| 34″ | 850 | 864.0 | 7.92 | 12.70 | 15.88 | 9.53 | 17.48 | 12.70 | |||||||||||
| 36″ | 900 | 914.0 | 7.92 | 12.70 | 15.88 | 9.53 | 19.05 | 12.70 | |||||||||||
| 38″ | 950 | 965.0 | 9.53 | 12.70 | |||||||||||||||
| 40″ | 1000 | 1016.0 | 9.53 | 12.70 | |||||||||||||||
| 42″ | 1050 | 1067.0 | 12.70 | 15.88 | 9.53 | 19.05 | 12.70 | ||||||||||||
| 44″ | 1100 | 1118.0 | 9.53 | 12.70 | |||||||||||||||
| 46″ | 1150 | 1168.0 | 9.53 | 12.70 | |||||||||||||||
| 48″ | 1200 | 1219.0 | 9.53 | 12.70 | |||||||||||||||
Reading the Chart
- OD is fixed per size. Every schedule of one NPS shares the same outside diameter; the wall grows inward.
- NPS 1/8″ to 12″: the nominal size is not the OD. NPS 2 is 60.3 mm OD. From NPS 14 up, OD equals the NPS in inches.
- STD, XS, XXS are the older weight classes. STD = SCH 40 and XS = SCH 80 only up to NPS 10 and NPS 8.
- S schedules (5S, 10S, 40S, 80S) are stainless steel per ASME B36.19M.
Quick Formulas
- Inside diameter: ID = OD − 2t
- Carbon steel weight: kg/m = (OD − t) × t × 0.02466
- Stainless steel: about 1% heavier than carbon steel
- Flow area: π/4 × ID²
Pipe Schedule Questions
What is a pipe schedule?
The schedule (SCH) number sets the wall thickness for a given nominal pipe size. The outside diameter stays the same for every schedule of one size, so a higher schedule means a thicker wall and a smaller bore. SCH 40 and SCH 80 are the most common for process and utility piping.
What is the difference between SCH 40 and STD?
Up to NPS 10 they are identical. From NPS 12 upward STD stays at 9.53 mm (0.375 in) while SCH 40 keeps getting thicker, so they differ. XS and SCH 80 likewise match up to NPS 8 only.
What do 5S, 10S, 40S and 80S mean?
The S schedules come from ASME B36.19M for stainless steel pipe. 40S and 80S match SCH 40 and SCH 80 up to NPS 10; the thin-wall 5S and 10S are used where corrosion resistance matters more than pressure rating.
How do I find the inside diameter?
ID = OD − 2 × wall thickness. For NPS 2 SCH 40: 60.3 − 2 × 3.91 = 52.48 mm. Tap any wall thickness in the chart to see the ID and weight per metre.
How do I calculate pipe weight per metre?
For carbon steel: kg/m = (OD − t) × t × 0.02466, with OD and wall thickness t in mm. Stainless steel is about 1% heavier. Use the Weight Calculator for other materials or total weight for a length.
What is the difference between NPS and DN?
NPS (Nominal Pipe Size, inches) and DN (Diamètre Nominal, mm) are trade names for the same size, not measured dimensions. NPS 2 = DN 50, but its actual outside diameter is 60.3 mm.
Nominal dimensions per ASME B36.10M and B36.19M for reference. Mill tolerance on wall thickness is typically −12.5%. Verify against the current standard and your pipe specification before use. Need pipe spools, flanged assemblies or machined pipe parts? Send us your drawing.