Pipe Schedule Chart
Nominal pipe size, outside diameter, wall thickness, inside diameter and weight per foot, covering NPS 1/8 through 48 and DN 6 through 1200 in carbon steel, stainless steel and PVC.
NPS stands for Nominal Pipe Size, the inch based label used in North America. DN stands for Diamètre Nominal, the millimetre based label used in Europe and much of Asia. Both are labels rather than measurements, which is the single thing that trips people up most often on a pipe schedule chart.
Dimensions follow ASME B36.10M for carbon and alloy steel, ASME B36.19M for stainless and nickel alloy, and ASTM D1785 for PVC. EN 10220, ISO 4200 and AS/NZS 1074 are cross-referenced further down the page.
Selected
6" Sch STD
DN 150, outside diameter 6.625 in, carbon steel
Wall thickness
0.280
in
Inside diameter
6.065
in
Weight, empty
18.97
lb/ft
Weight, water filled
31.50
lb/ft
The Master Pipe Schedule Chart
Pick the standard you are working to, then the schedule you need. One schedule gives you a clean table of every size with OD, wall, bore and weight. All schedules gives you the full grid, where every cell is clickable and the strip above shows the complete dimensions for whatever you pick. The link in your address bar updates, so you can bookmark or share the exact view.
Carbon steel, all schedules per ASME B36.10M
Wall thickness in inches| NPS | DN | OD | 5S | 10S | 10 | 20 | 30 | STD | 40 | 60 | XS | 80 | 100 | 120 | 140 | 160 | XXS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/8" | 6 | 0.405 | 0.035 | 0.049 | — | — | — | 0.068 | 0.068 | — | 0.095 | 0.095 | — | — | — | — | — |
| 1/4" | 8 | 0.540 | 0.049 | 0.065 | — | — | — | 0.088 | 0.088 | — | 0.119 | 0.119 | — | — | — | — | — |
| 3/8" | 10 | 0.675 | 0.049 | 0.065 | — | — | — | 0.091 | 0.091 | — | 0.126 | 0.126 | — | — | — | — | — |
| 1/2" | 15 | 0.840 | 0.065 | 0.083 | — | — | — | 0.109 | 0.109 | — | 0.147 | 0.147 | — | — | — | 0.188 | 0.294 |
| 3/4" | 20 | 1.050 | 0.065 | 0.083 | — | — | — | 0.113 | 0.113 | — | 0.154 | 0.154 | — | — | — | 0.219 | 0.308 |
| 1" | 25 | 1.315 | 0.065 | 0.109 | — | — | — | 0.133 | 0.133 | — | 0.179 | 0.179 | — | — | — | 0.250 | 0.358 |
| 1-1/4" | 32 | 1.660 | 0.065 | 0.109 | — | — | — | 0.140 | 0.140 | — | 0.191 | 0.191 | — | — | — | 0.250 | 0.382 |
| 1-1/2" | 40 | 1.900 | 0.065 | 0.109 | — | — | — | 0.145 | 0.145 | — | 0.200 | 0.200 | — | — | — | 0.281 | 0.400 |
| 2" | 50 | 2.375 | 0.065 | 0.109 | — | — | — | 0.154 | 0.154 | — | 0.218 | 0.218 | — | — | — | 0.344 | 0.436 |
| 2-1/2" | 65 | 2.875 | 0.083 | 0.120 | — | — | — | 0.203 | 0.203 | — | 0.276 | 0.276 | — | — | — | 0.375 | 0.552 |
| 3" | 80 | 3.500 | 0.083 | 0.120 | — | — | — | 0.216 | 0.216 | — | 0.300 | 0.300 | — | — | — | 0.438 | 0.600 |
| 3-1/2" | 90 | 4.000 | 0.083 | 0.120 | — | — | — | 0.226 | 0.226 | — | 0.318 | 0.318 | — | — | — | — | 0.636 |
| 4" | 100 | 4.500 | 0.083 | 0.120 | — | — | — | 0.237 | 0.237 | 0.281 | 0.337 | 0.337 | — | 0.438 | — | 0.531 | 0.674 |
| 5" | 125 | 5.563 | 0.109 | 0.134 | — | — | — | 0.258 | 0.258 | — | 0.375 | 0.375 | — | 0.500 | — | 0.625 | 0.750 |
| 6" | 150 | 6.625 | 0.109 | 0.134 | — | — | — | 0.280 | 0.280 | — | 0.432 | 0.432 | — | 0.562 | — | 0.719 | 0.864 |
| 8" | 200 | 8.625 | 0.109 | 0.148 | — | 0.250 | 0.277 | 0.322 | 0.322 | 0.406 | 0.500 | 0.500 | 0.594 | 0.719 | 0.812 | 0.906 | 0.875 |
| 10" | 250 | 10.750 | 0.134 | 0.165 | — | 0.250 | 0.307 | 0.365 | 0.365 | 0.500 | 0.500 | 0.594 | 0.719 | 0.844 | 1.000 | 1.125 | 1.000 |
| 12" | 300 | 12.750 | 0.156 | 0.180 | — | 0.250 | 0.330 | 0.375 | 0.406 | 0.562 | 0.500 | 0.688 | 0.844 | 1.000 | 1.125 | 1.312 | 1.000 |
| 14" | 350 | 14.000 | — | — | 0.250 | 0.312 | 0.375 | 0.375 | 0.438 | 0.594 | 0.500 | 0.750 | 0.938 | 1.094 | 1.250 | 1.406 | — |
| 16" | 400 | 16.000 | — | — | 0.250 | 0.312 | 0.375 | 0.375 | 0.500 | 0.656 | 0.500 | 0.844 | 1.031 | 1.219 | 1.438 | 1.594 | — |
| 18" | 450 | 18.000 | — | — | 0.250 | 0.312 | 0.438 | 0.375 | 0.562 | 0.750 | 0.500 | 0.938 | 1.156 | 1.375 | 1.562 | 1.781 | — |
| 20" | 500 | 20.000 | — | — | 0.250 | 0.375 | 0.500 | 0.375 | 0.594 | 0.812 | 0.500 | 1.031 | 1.281 | 1.500 | 1.750 | 1.969 | — |
| 24" | 600 | 24.000 | — | — | 0.250 | 0.375 | 0.562 | 0.375 | 0.688 | 0.969 | 0.500 | 1.219 | 1.531 | 1.812 | 2.062 | 2.344 | — |
| 30" | 750 | 30.000 | — | — | 0.312 | 0.500 | 0.625 | 0.375 | — | — | 0.500 | — | — | — | — | — | — |
| 36" | 900 | 36.000 | — | — | 0.312 | 0.500 | 0.625 | 0.375 | 0.750 | — | 0.500 | — | — | — | — | — | — |
| 42" | 1050 | 42.000 | — | — | — | — | — | 0.375 | — | — | 0.500 | — | — | — | — | — | — |
| 48" | 1200 | 48.000 | — | — | — | — | — | 0.375 | — | — | 0.500 | — | — | — | — | — | — |
ASME B36.10M governs the wall thickness values. Weights calculated at 0.2836 lb per cubic inch. Verify wall thickness against the current standard before issuing anything for purchase.
Want this chart at the desk? Download the whole thing, lookup included, as one HTML file for the shared drive.
Schedule 40 Pipe Dimensions
Schedule 40 is the default wall for most utility, plumbing and general process service, and it is the schedule people mean when they say standard weight pipe. Through NPS 10 schedule 40 and STD are identical. From NPS 12 upward they separate, because STD holds at 0.375 inch for every larger size while schedule 40 keeps climbing.
Open Schedule 40 in the chart aboveSchedule 80 Pipe Dimensions
Schedule 80 is the common step up for higher pressure, for small bore lines that need mechanical robustness, and for services where a corrosion allowance has to be carried in the wall. Through NPS 8 schedule 80 and XS are identical, and above that XS holds at 0.500 inch while schedule 80 continues to thicken.
Open Schedule 80 in the chart aboveWhat A Pipe Schedule Actually Means
Outside diameter is fixed for a given nominal size, so a schedule change moves the wall inward and shrinks the bore while the outside stays exactly where it was. That is why a 6 inch line keeps the same flange, fitting, support and insulation dimensions across every schedule, and why a spec upgrade late in a bid changes weight and weld time without changing the routing.
The relationship between size and outside diameter is also not intuitive below NPS 14. A 2 inch pipe measures 2.375 inches across the outside, and a 12 inch pipe measures 12.750 inches. From NPS 14 upward the outside diameter equals the nominal number, so 24 inch pipe is 24 inches across.
A schedule number is a dimensional designation and not a pressure rating. Allowable pressure depends on the material grade, the design temperature, the corrosion allowance and the governing code, which for process piping in the United States is usually ASME B31.3.
Where The Schedule Moves Your Estimate
Weight drives freight, rigging, support steel and hanger sizing, and it moves several times over across the schedule range for a single size. A 6 inch line is 18.97 lb/ft in STD and 53.16 lb/ft in XXS.
Wall thickness drives weld time, since a heavier wall means more passes and a larger bevel volume for the same diameter inch.
Inside diameter drives the hydraulic check, and it is the number that shifts when a schedule upgrade lands after the line sizing was done.
Mill tolerance on wall thickness is plus or minus 12.5 percent of nominal, so the pipe you receive can be meaningfully lighter or heavier than the table value.
Material Specs Are Not Dimension Specs
ASTM A53, A106 and A312 define the steel, the manufacturing route and the testing. They do not define dimensions. A line called out as A106 Gr B, 6 inch, schedule 40 takes its grade from ASTM and its 0.280 inch wall from ASME B36.10M.
The Standards Behind The Chart
United States
ASME B36.10M is the base standard. It sets the dimensional relationship between nominal pipe size, schedule number and wall thickness for welded and seamless wrought carbon and alloy steel pipe. Schedules run 5, 10, 20, 30, 40, 60, 80, 100, 120, 140 and 160, alongside the older STD, XS and XXS designations that predate the numbering.
ASME B36.19M does the same job for stainless and nickel alloy pipe, and it is where the S suffix schedules come from. In the smaller sizes 5S and 10S are thinner than anything in the carbon table, which is why thin wall stainless exists at 1/2 inch and thin wall carbon does not. In the larger sizes 40S holds at 0.375 inch and 80S holds at 0.500 inch rather than continuing to climb.
API 5L covers line pipe, and it uses the same NPS dimensional tables, so the schedule chart carries across.
ASTM D1785 covers rigid PVC pipe in schedules 40, 80 and 120. PVC reuses the steel outside diameters and the schedule 40 and 80 wall thicknesses, so the geometry matches while the weight does not.
Europe: EN 10220 And ISO 4200
Europe does not use schedule numbers. You specify outside diameter and wall thickness directly in millimetres, and EN 10220 sets the dimensions and the mass per metre, aligned with ISO 4200. Outside diameters fall into Series 1, where all accessories are standardised, Series 2, where some are, and Series 3, where very few are.
Material and delivery conditions sit in EN 10216 for seamless and EN 10217 for welded, while the dimensions stay with EN 10220.
Most DN values map cleanly onto an NPS size, but a few do not line up exactly, and those are the ones worth catching on a cross-border job.
Open the EN 10220 table in the chart above
Australia And New Zealand: AS/NZS 1074
AS/NZS 1074 covers steel tubes and tubulars for ordinary service from DN 8 to DN 150. It designates wall thickness as Light, Medium and Heavy rather than by schedule number, so a direct conversion does not exist. As a rough orientation, Medium sits near schedule 40 in the mid sizes and Light sits well below schedule 10, though the outside diameters differ at DN 150 where AS/NZS 1074 uses 165.1 mm against 168.3 mm in EN 10220.
Two adjacent standards come up often and are worth keeping separate. AS/NZS 1163 covers cold formed structural hollow sections in grades C250, C350 and C450, which is structural steel rather than conveyance. AS 1579 covers welded steel pipe for water transmission, wastewater and pipe piles. AS 4041 is the pressure piping design code, the local counterpart to ASME B31.3, and it governs the wall thickness calculation rather than publishing a dimension table.
In practice, Australian process, oil and gas piping is normally specified to ASME B36.10M and B36.19M anyway, so the main chart above applies. The local standards matter most for water, structural and general service work.
Open the AS/NZS 1074 table in the chart above
Frequently asked questions
A pipe schedule is a wall thickness designation. Outside diameter is fixed for a given nominal pipe size, so the schedule number tells you how far the wall is set inward from that fixed outside diameter. A higher schedule number means a thicker wall, a smaller bore and a heavier pipe, with the outside dimension unchanged.
Schedule 40 is the most common wall thickness in general process, utility and plumbing service. Through NPS 10 it matches the traditional Standard weight designation, so a 6 inch schedule 40 line and a 6 inch STD line are the same 0.280 inch wall. From NPS 12 upward the two separate, and 12 inch schedule 40 runs 0.406 inch against 0.375 inch for STD.
It means the pipe is manufactured to the schedule 40 wall thickness listed against its nominal size in ASME B36.10M. The number is a dimensional label rather than a pressure rating, and the pressure a line can hold also depends on material grade, temperature, corrosion allowance and the design code.
Schedule 40 wall thickness changes with pipe size. It runs 0.109 inch at 1/2 inch, 0.154 inch at 2 inch, 0.237 inch at 4 inch, 0.280 inch at 6 inch, 0.322 inch at 8 inch and 0.365 inch at 10 inch. Mill tolerance on wall thickness is plus or minus 12.5 percent of the nominal value.
Schedule 80 wall thickness also changes with size. It runs 0.147 inch at 1/2 inch, 0.218 inch at 2 inch, 0.337 inch at 4 inch, 0.432 inch at 6 inch and 0.500 inch at 8 inch. Through NPS 8 schedule 80 matches the Extra Strong designation.
In carbon steel, schedule 10 starts at NPS 8 and carries a 0.250 inch wall through NPS 24. In stainless the equivalent is schedule 10S, which is thinner in the small sizes, running 0.083 inch at 1/2 inch, 0.109 inch at 2 inch, 0.134 inch at 6 inch and 0.148 inch at 8 inch.
Take The Chart With You
The full interactive chart as a single HTML file: carbon steel, stainless and PVC in inches and millimetres, with the size lookup still working offline.
Stop Looking Wall Thickness Up By Hand
The Takeoff AI reads your isometrics and P&IDs, pulls every line size and spec, and returns a material takeoff with schedule, wall and weight already applied.
Book a demoPart of The Takeoff Handbook. Wall thickness values are transcribed from the governing standards, while inside diameter and weight are calculated from outside diameter and wall. Reference data supports estimating work and does not replace the governing project specification.