Pipe Weight per Foot and per Metre

Pipe Weight Chart: Schedule 40 and Schedule 80

The two most commonly specified series, 50 rows, in carbon steel. Weight is the last two columns; the dimensions it was computed from are the ones beside it.

Showing 50 of 50 rows

Showing ASME B36.10M-2015. 766 of 772 rows verified against the standard itself; every figure is checked against the standard’s own mass formula. How this data was verified.

Schedules 5 through 160, plus STD, XS and XXS, carry their own weights at every size. The full pipe size chart has all of them, and schedule 40 pipe dimensions covers that series on its own.

The Formula, Not the Table

Pipe weight is not a measured quantity. It is arithmetic on two dimensions, and every standard that publishes a mass column also publishes the formula that produced it:

W = (OD − t) × t × C

OD is the outside diameter and t the wall thickness. C carries the density and the units: 10.69 gives pounds per foot from inches, 0.02466 gives kilograms per metre from millimetres, both for carbon steel at 7.85 g/cm³. For NPS 2 schedule 40 that is:

(2.375 − 0.154) × 0.154 × 10.69 = 3.66 lb/ft
(60.3 − 3.91) × 3.91 × 0.02466 = 5.44 kg/m

Recomputing the whole standard this way is also how the dataset is checked: a mistyped wall thickness produces a mass that no longer agrees with its own row. How this data was verified sets out what that check has caught.

Where the Constant Comes From

C is not a lookup value. In metric units it is π times the density in grams per cubic centimetre, divided by a thousand: π × 7.85 ÷ 1000 = 0.024661, which the standards print as 0.02466. Ductile iron at 7.05 g/cm³ gives 0.0221482 by the same arithmetic. That is the whole derivation, and it is why the constant is a property of the material rather than of the pipe.

The Constant Is Material-Specific

This is the expensive mistake. The steel constant is quoted so widely that it gets applied to iron, and iron is markedly lighter — 7.05 g/cm³ against 7.85.

Using 0.02466 on ductile iron overstates the mass by 11.3% — the ratio of the two densities, applied to every row of a bill of materials at once. On a shipment priced by the tonne, that is not a rounding difference.

The carbon-steel constants are printed inside the standards themselves, in ASME B36.10M, ISO 4200 clause 4, GOST 8732 and IS 3589 clause 11.1.1. The ductile-iron figure of 9.60 lb/ft is not quoted from a standard held here: it is 10.69 scaled by the density ratio, shown so that the arithmetic behind it is visible.

These Figures Are Carbon Steel

Said plainly, because most weight charts are not: the table above is carbon steel to ASME B36.10M-2015, and nothing else. 766 of its 772 rows are verified against that standard itself.

Stainless dimensions to ASME B36.19M are held here too, but they rest on a single publisher, so no stainless weight table is published — the publication policy does not allow a single-source figure to be shown as fact. There are no PVC, copper, HDPE or ductile-iron weight tables on this site at all. For those, the formula above with the material’s own constant is the reliable route; a steel chart is not.

Why This Weight May Differ From a Printed Chart

Small disagreements between weight tables are usually not errors. They are three specific artefacts, and each is worth recognising.

The Printed Mass Column Is Rounded

Published mass columns run to two decimal places, which at the small end is coarse. At ⅛-inch schedule 40 the published figure is 0.24 lb/ft where the formula returns 0.245 — a 2% gap that is entirely rounding, because half a unit in the second decimal place is 2% of a number that small. Neither figure is wrong; what matters is which one a chart is quoting, and this site always quotes the formula.

Per Foot and Per Metre Are Computed Separately

The inch and millimetre dimension columns are rounded independently in the standard — outside diameters to 0.1 mm up to 16 in and to the nearest millimetre above it, walls to 0.01 mm. Each unit system is therefore computed from its own dimensions, and converting one result into the other does not always reproduce the figure computed in that other unit. At ⅛ inch schedule 40, 0.245 lb/ft converts to 0.365 kg/m, while the metric dimensions give 0.366. Neither is wrong.

Some Standards Weigh a Different Pipe

ISO 65, EN 10255, AS 1074 and IS 1239 compute mass from the mean of the outside-diameter tolerance band rather than from the nominal outside diameter. A threadable-tube weight from one of those standards is answering a slightly different question from an ASME weight, even at the same DN. NPS to DN conversion covers where those designations do and do not line up.

What Actually Changes a Pipe’s Weight

Only the wall, at a given size. Outside diameter is fixed by the nominal size and identical in every schedule, so the entire difference between 3.66 lb/ft and 5.03 lb/ft for 2-inch pipe is schedule 80’s extra 0.064 in of wall. The name on the pipe does not enter the calculation at all — see nominal pipe size explained for why that name is not a measurement.

The Same Size Weighs Something Else Abroad

Mass follows the diameter, and the diameter is not the same everywhere. A pipe sold as 2½ inch or DN 65 is 73.0 mm across the outside under ASME B36.10M and 76.3 mm under JIS — so the figures in the table above are the American answer, not the universal one.

Both standards publish a schedule 40 at that size, which makes the comparison exact rather than hypothetical. ASME gives a 5.16 mm wall at 8.63 kg/m; JIS G3454:2019 gives a 5.2 mm wall at 9.12 kg/m. That is 0.49 kg/m, or 5.6% more per metre for the same designation — enough to matter on a lorry, a hanger schedule or a quotation.

Most of the world does not use schedules at all. EN 10220 (56 countries), the BS 1387 and ISO 65 lineage (46), GOST (15) and GB/T (1) specify an outside diameter and a wall directly, which is the more useful way to ask for pipe anywhere the schedule number is not local. Which series applies where is set out in pipe standards by country, covering 157 of them.

Frequently Asked Questions

How much does 2-inch schedule 40 pipe weigh?

3.66 lb per foot, or 5.44 kg per metre, in carbon steel. That is the standard's own formula evaluated on an outside diameter of 2.375 in and a wall of 0.154 in, not a figure copied from another chart.

How do you calculate pipe weight per foot?

Subtract the wall thickness from the outside diameter, multiply by the wall thickness, then multiply by 10.69 for pounds per foot from inches. The same formula with 0.02466 gives kilograms per metre from millimetres.

What is the constant 10.69 in the pipe weight formula?

It is the density of carbon steel folded into the units: pi times 0.2836 lb per cubic inch times 12 inches per foot. Change the material and the constant changes with it.

Does ductile iron use the same weight formula as steel?

The formula is identical; the constant is not. Ductile iron is 7.05 g/cm3 against carbon steel's 7.85, giving 0.0221482 kg/m where steel gives 0.02466. Using the steel constant on iron overstates the mass by 11.3%.

Does the schedule change the weight of a pipe?

Yes, and at a given size it is the only thing that does. The outside diameter is fixed by the nominal size, so a heavier schedule is entirely extra wall: 2-inch schedule 80 is 5.03 lb/ft against schedule 40's 3.66.