Metal weight and pipe dimensions, computed rather than copied
16 materials × 10 section shapes = 160 size-series tables, plus 31 nominal pipe sizes across 17 ASME schedules. Every figure on every page is computed as area × length × density from closed-form geometry and a specification density — nothing is interpolated, and nothing is copied from a published weight chart.
Two clusters, one method
Both halves of the site answer the same physical question in different geometry, so they share a single calculation path. A hollow section and a pipe are the same calculation with a different outside diameter; a round bar is the same calculation with a zero bore.
Metal weight
16 materials from HDPE at 960 kg/m³ to lead at 11,340 kg/m³, across 10 section shapes. Areas from geometry, densities from the specification each grade represents.
Pipe dimensions and schedules
The full ASME B36.10M and B36.19M tabulation: outside diameter, wall thickness by schedule, inside diameter, metal area, mass and water capacity for 31 nominal sizes.
Carbon steel, every shape, at one reference size
One row per section shape at the site’s standard reference size, so the area and mass columns are a genuine comparison. Change the material on any of these pages and the area column stays identical — because area is geometry, and only mass depends on density.
| Section | Reference sizemm | Areamm² | Mass | Imperial |
|---|---|---|---|---|
| Round Bar A = π/4 · d² | d 25 | 490.9 | 3.853 kg/m | 2.589 lb/ft |
| Square Bar A = a² | a 25 | 625.0 | 4.906 kg/m | 3.297 lb/ft |
| Hexagonal Bar A = (√3/2) · AF² ≈ 0.8660 · AF² | AF 24 | 498.8 | 3.916 kg/m | 2.631 lb/ft |
| Flat Bar A = w · t | w 50 × t 6 | 300.0 | 2.355 kg/m | 1.582 lb/ft |
| Plate A = w · t | w 1000 × t 10 | 10,000.0 | 78.500 kg/m² | 16.078 lb/ft² |
| Round Tube A = π/4 · (D² − d²), d = D − 2t | D 50 × t 3 | 443.0 | 3.477 kg/m | 2.337 lb/ft |
| Square Tube A = a² − (a − 2t)² | a 40 × t 3 | 444.0 | 3.485 kg/m | 2.342 lb/ft |
| Angle (L Section) A = t · (a + b − t) | a 50 × b 50 × t 5 | 475.0 | 3.729 kg/m | 2.506 lb/ft |
Plate is quoted per square metre because it is bought by area; every other shape is per metre of length. All 160 material × shape combinations are published — start from all 16 materials or all 10 sections .
Schedule 40 pipe, the sizes that get ordered
Sch 40 is the default wall for most steel pipework, and it is the schedule every printed chart includes — which makes it the one worth showing where a reader can check it against a source they already trust. Carbon steel at 7,850 kg/m³.
| Nominal size | Outside dia.mm | Wallmm | Inside dia.mm | Masskg/m | Imperiallb/ft |
|---|---|---|---|---|---|
| NPS 1/2 (DN 15) | 21.3 | 2.77 | 15.8 | 1.268 | 0.852 |
| NPS 1 (DN 25) | 33.4 | 3.38 | 26.6 | 2.501 | 1.681 |
| NPS 2 (DN 50) | 60.3 | 3.91 | 52.5 | 5.442 | 3.657 |
| NPS 3 (DN 80) | 88.9 | 5.49 | 77.9 | 11.286 | 7.584 |
| NPS 4 (DN 100) | 114.3 | 6.02 | 102.3 | 16.075 | 10.802 |
| NPS 6 (DN 150) | 168.3 | 7.11 | 154.1 | 28.267 | 18.994 |
| NPS 8 (DN 200) | 219.1 | 8.18 | 202.7 | 42.538 | 28.584 |
| NPS 12 (DN 300) | 323.8 | 10.31 | 303.2 | 79.739 | 53.582 |
A 4-inch pipe does not have a 4-inch outside diameter — it is 4.500 in / 114.3 mm, and it has not been 4 inches since the 1930s. NPS 4 and DN 100 are two names for the same dimensionless size, and neither one is a measurable dimension. The outside diameter is the governed dimension and it is on every page; see DN to NPS conversion for the full mapping.
Calculators, when a table is the wrong shape
A table cannot answer “given these exact dimensions” or “given a mass limit”. The two calculators can, and they use the same calculation path as the tables — so a figure from a table and a figure from a calculator agree to the last digit by construction, not by luck.
Metal weight calculator
Any dimensions, any material, a multi-line bill of materials with a running total, and a reverse lookup: give it a mass limit and it returns the length you can have.
Pipe weight calculator
Outside diameter and wall thickness to mass per metre and per foot, plus the two outputs a printed pipe chart cannot give you: water capacity per metre and external surface area for coating quantities.
Download the data
CSV, generated at build time
Every table on the site, as a flat file produced from the same source the pages render — so the download and the page cannot disagree.
Licence, column definitions and provenance are on the downloads page.
How every number on this site is produced
There is one identity behind both clusters:
m = A × 10⁻⁶ × ρ
where A is the cross-sectional area in mm², ρ the density in kg/m³, and m the mass in kg/m. Three consequences follow, and each one is a way people get this wrong:
- Area depends only on geometry. Changing material never changes the area column. That is why the area matrix on each tube page is identical for all 16 materials.
- Mass is exactly linear in density. A 1 % density error is a 1 % weight error. Substituting 316 for carbon steel is about +1.9 %.
- Mass is quadratic in a round bar’s diameter, linear in a plate’s thickness. A small diameter change moves weight much faster than a small thickness change does.
We do not tabulate section properties, and we do not publish pressure ratings. Both need a code and a temperature-dependent allowable stress, not just geometry, and reproducing them badly would be worse than not having them. Weight is a mass property: it does not tell you whether a part is strong enough or safe. The full statement — including every source and its edition — is on methodology and sources.
Frequently asked questions
What is this site?
A reference for two things a fabricator or estimator looks up constantly: how much a piece of metal weighs, and what the dimensions of a pipe are. It covers 16 materials across 10 section shapes — 160 size-series tables — and the full ASME B36.10M / B36.19M pipe schedule range from NPS 1/8 to NPS 36 in 17 schedules.
Where do the numbers come from?
Every weight is computed as area × length × density. The areas come from the closed-form geometry of each shape, not from a table; the densities come from the material specifications named on each material page. Pipe dimensions are the tabulated values from ASME B36.10M (welded and seamless wrought steel) and B36.19M (stainless steel). Nothing here is transcribed from someone else’s weight chart.
Why does this differ from the chart my supplier emailed me?
Almost always density. Most printed steel charts are computed at a nominal 0.2833–0.2836 lb/in³ — roughly 7,844 to 7,850 kg/m³ — and then rounded. This site computes at the specification density of the material you choose, so the difference between a mill chart and these figures is usually in the third or fourth significant figure, and a 304 stainless figure is about 1.9 % heavier than the carbon steel figure for identical geometry.
Is this safe to use for a purchase order?
For an estimate, yes. For a contract, buy against the mill certificate. Nominal density is not the density of a specific heat of material, and wrought grades vary within the ranges published on the density chart. On a handrail the difference does not matter; on a 40-tonne fabricated order a 1 % density difference is 400 kg, which is real money.
Why is there no strength or pressure rating?
Because weight does not determine either one. A pressure rating needs the wall thickness, the material’s allowable stress at temperature, the design code and the corrosion allowance; a structural check needs the second moment of area and the actual load case. Cross-sectional area — which is on every page here — is one input to those calculations, not the answer. Pressure-rating and section-property tables are on the roadmap and deliberately not published until they can be done properly.
What has not been built yet?
Pressure ratings, section properties for named structural shapes (UPN, IPE, HEA, AISC W/C/MC), bolt torque, flanges and a cost calculator. The reasons each is deferred are stated on the calculators page rather than left as a gap.
Go deeper
The hubs, the calculators, and the pages that state where the numbers come from.
- Metal weight overview — how the calculation works
- All 16 materials — densities and specifications
- All 10 sections — formulas and size series
- All pipe schedules — Sch 5S to XXS
- All nominal sizes — NPS 1/8 to NPS 36
- Download the data — CSV, generated from the same source
- Cross-reference tables — DN / NPS / material equivalents
- Methodology and sources — where every number comes from
Areas computed from closed-form geometry for 10 section types. Pipe dimensions from ASME B36.10M-2018 and ASME B36.19M-2018. Densities are nominal specification values, one per material grade. Unit conversions use the definitional constants 25.4 mm/in, 0.3048 m/ft and 0.45359237 kg/lb. Data version and review date are recorded on every page.
- Elementary plane geometry. The circle, polygon and hollow-section area formulas.
- ASTM material specifications for each grade named in the material entry (A36, A240/A276, B209/B211/B221, B152/B16/B505, B265/B348, A48, B29, D1784, D3350).
- ISO 4427 / ASTM D3350 — polyethylene pipe compounds (PE 100 material classification).
- BIPM / NIST definitional constants: international inch = 25.4 mm, foot = 0.3048 m, pound = 0.45359237 kg.
Dataset version 2026.09.1 · dimensions last verified against source 2026-09-21. Found an error? Report it — corrections are issued with a version bump.