Metal Tonnage
Calculator
Weight for pipe and structural shapes across nine materials. Build a line-item estimate, or upload the whole line list, and get your total in pounds and short tons.
Price a line, one at a time.
Pick a size, a schedule and a material, or a rolled shape from the AISC catalogue. The unit weight appears before you commit the line, so you can sanity-check it against the mill certificate in front of you.
Or bring the whole line list.
Download the template, paste your line items into the Pipe, Structural and Plate sheets, and upload it back. Rows that don't resolve to a published size are reported line by line rather than silently dropped.
Three sheets, pre-filled with sample rows. A single-table CSV works too — the header row decides which sheet it is read as.
What's in the catalogue
Every number the calculator uses, in the open. If a figure here disagrees with your mill certificate, trust the certificate.
k folds π × density × 12 into one constant, so pipe weight per foot is k × t × (OD − t).
| Material | Density lb/in³ | Constant k | 4" Sch 40 lb/ft |
|---|---|---|---|
| Carbon Steel (A106 / A53) | 0.2836 | 10.6802 | 10.79 |
| Stainless 304 / 304L | 0.2900 | 10.9213 | 11.03 |
| Stainless 316 / 316L | 0.2900 | 10.9326 | 11.05 |
| Chrome-Moly (P11 / P22) | 0.2836 | 10.6802 | 10.79 |
| Aluminum 6061 | 0.0975 | 3.6714 | 3.71 |
| Copper (C12200) | 0.3230 | 12.1494 | 12.27 |
| Nickel Alloy (Inconel 625) | 0.3050 | 11.4864 | 11.61 |
| Titanium Gr. 2 | 0.1630 | 6.1464 | 6.21 |
| Duplex Stainless (2205) | 0.2780 | 10.4693 | 10.58 |
How the weight is calculated
Outside diameter and wall thickness come from ASME B36.10M for carbon and alloy pipe, B36.19M for the stainless S schedules. The result is pounds per foot; multiply by the run length.
Rolled shapes carry a published nominal weight per foot. For W and C shapes it is the number in the designation itself - a W8x31 is 31 lb/ft. Angles and HSS are looked up in the AISC tables.
Thickness, width and length in inches give cubic inches; the A36 density of 0.2836 lb/in³ converts that to pounds. Quantity multiplies the piece weight.
Totals are short tons, the unit U.S. mills and fabricators quote in. Line totals are carried at full precision and rounded only for display, so the footer total will not drift from the sum of the rows.
Weights are for the run of pipe or the length of shape. Fittings, flanges, valves, welds, bolts, connection plates, coatings and insulation are not included - add them as their own lines or as a percentage allowance.
Wall thickness and shape weights are the published nominal values. Mill tolerance on pipe wall is typically -12.5%, so as-received weight runs under the calculated figure more often than over.
Tonnage is short tons at 2,000 lb. For metric tonnes divide pounds by 2,204.62; for long tons divide by 2,240.
Plate uses the A36 density of 0.2836 lb/in³. For stainless or aluminium plate, scale the result by the density ratio in the table above.
This calculator prices one line at a time. Your bid package has thousands.
theTakeoff.ai reads your P&IDs, isometrics and structural drawings and quantifies every line across every sheet - with each quantity tracing back to the drawing it came from, so the estimator keeps control of scope and pricing. Same standards, same arithmetic, run across the whole set instead of one row at a time.
The Metal Tonnage Calculator is published free by ContraVault AI, which builds ATLAS (thetakeoff.ai), an AI-native estimation engine for industrial contractors. It automates quantity takeoff across piping, structural, E&I, insulation and equipment, and every quantity traces back to the drawing it came from, so the estimator stays in control of scope, pricing and final accountability. Your line items are never uploaded - every weight on this page is worked out in your own browser.
