How the metal weight calculator works
Weight is volume times density. The calculator works out the area of the cross-section (the shape you’d see if you sawed the piece in half), multiplies it by the length to get volume, then multiplies by the metal’s density.
weight = cross-section area × length × density
For example, a 1/4 in steel plate 48 in wide and 8 ft long is 0.25 × 48 × 96 = 1,152 cubic inches. At0.2836 lb/in³ that is about 327 lb [1][2].
Cross-section formulas
| Shape | Area |
|---|---|
| Plate, sheet, flat bar | width × thickness |
| Round bar | π × d² ÷ 4 |
| Square bar | side² |
| Hex bar | 0.866 × (across flats)² |
| Round tube, pipe | π × wall × (OD − wall) |
| Square / rectangular tube | W × H − (W − 2·wall) × (H − 2·wall) |
| Angle | thickness × (leg A + leg B − thickness) |
| Channel | depth × t + 2 × (flange − t) × t |
Pipe uses the outside diameter and wall thickness for the size and schedule you pick, from the ASME B36.10 table[18]. Our results match published weight-per-foot tables for schedule 40 and 80 steel pipe to within 1% [19][20].
Densities used
Each default density is backed by at least two published data sheets or references. Choose “Other” to enter any density.
| Material | g/cm³ | lb/in³ | Sources |
|---|---|---|---|
| Carbon / mild steel (A36, 1018) | 7.85 | 0.2836 | [1][2] |
| Stainless steel 304 Published values range from 7.90 to 8.00 g/cm³, about 1%. | 8 | 0.2890 | [3][4] |
| Stainless steel 316 Published values range from 7.90 to 8.00 g/cm³, about 1%. | 8 | 0.2890 | [5][6] |
| Aluminum 6061 | 2.7 | 0.0975 | [7][8] |
| Aluminum 5052 | 2.68 | 0.0968 | [9][10] |
| Aluminum 7075 | 2.81 | 0.1015 | [11][12] |
| Brass C360 (free-cutting) | 8.5 | 0.3071 | [13][14] |
| Copper C110 One table lists 8.89 g/cm³ (about 0.5% lower). | 8.94 | 0.3230 | [15][2] |
| Titanium Ti-6Al-4V (grade 5) | 4.43 | 0.1600 | [16][17] |
Why real weights differ
- Mill tolerances. Plate, bar and tube are made to a tolerance band, so actual thickness and wall can vary from nominal.
- Corner and fillet radii. Tube corners are rounded and angles and channels have fillets and rounded toes. The formulas here assume sharp corners, so they usually read slightly heavy for tube and slightly off for structural shapes.
- Structural channel and beams. Hot-rolled American Standard channels have tapered flanges and a thinner web than flange. Their nominal weight is part of the name: a C6×8.2 weighs 8.2 lb/ft. Use this calculator’s channel for bent or uniform-thickness channel.
- Alloy and temper. Densities vary slightly between alloys in the same family, and coatings such as galvanizing add weight.
Results are theoretical estimates for shipping, handling and purchasing. Don’t use them for structural or load design.
Common questions
How do you calculate the weight of steel?
Multiply the volume by steel’s density, about 0.2836 lb per cubic inch (490 lb per cubic foot) or 7.85 g/cm³[1][2]. For bar and tube, find the cross-section area first, then multiply by length.
How much does a 4 × 8 sheet of 1/4 in steel weigh?
About 327 lb (148 kg). Every square foot of 1/4 in steel plate weighs about 10.2 lb, and a 4 × 8 sheet is 32 square feet.
How much does 2 × 2 × 1/8 in square tube weigh per foot?
About 3.19 lb/ft in steel by the sharp-corner formula, so a 20 ft stick is about 64 lb. Real tube with rounded corners comes in a little lighter.
Is there a quick formula for round steel bar in kg per meter?
Yes. For steel at 7.85 g/cm³, kg/m ≈ d² ÷ 162 with d in millimeters. A 20 mm bar is 400 ÷ 162 ≈ 2.47 kg/m. It follows directly from π × d² ÷ 4 × density.
How much lighter is aluminum than steel?
6061 aluminum is about 2.70 g/cm³ against 7.85 for steel, so the same size piece weighs about 34% as much[7][1].
Does stainless steel weigh more than carbon steel?
Slightly. 304 and 316 stainless are about 7.9–8.0 g/cm³, roughly 1–2% heavier than carbon steel[3][4][5][6].
Sources
- AZoM, “ASTM A36 Mild/Low Carbon Steel”Carbon steel density 7.85 g/cm³ (0.284 lb/in³)
- The Engineering ToolBox, “Metals and Alloys: Densities”Steel 7850 kg/m³; copper 8940 kg/m³; stainless range 7480–8000 kg/m³
- AZoM, “Stainless Steel: Grade 304 (UNS S30400)”304 density 8000 kg/m³
- Wikipedia, “SAE 304 stainless steel”304 density 7900 kg/m³ (0.286 lb/in³)
- AZoM, “Stainless Steel: Grade 316 (UNS S31600)”316 density 8000 kg/m³
- Sandmeyer Steel, “316/316L Stainless Steel Plate”316 density 7.90 g/cm³ (0.285 lb/in³)
- Alloys International, “Aluminum 6061”6061 density 2.7 g/cm³ (0.0975 lb/in³)
- Wikipedia, “6061 aluminium alloy”6061 density 2.70 g/cm³
- AZoM, “Aluminium / Aluminum 5052 Alloy (UNS A95052)”5052 density 2.68 g/cm³ (0.0968 lb/in³)
- Wikipedia, “5052 aluminium alloy” (citing ASM Handbook vol. 2)5052 density 2.68 g/cm³
- Alloys International, “Aluminum 7075”7075 density 2.81 g/cm³ (0.102 lb/in³)
- Wikipedia, “7075 aluminium alloy”7075 density 2.81 g/cm³
- Fisk Alloy, “C36000 Free-Cutting Brass”C360 density 8.5 g/cm³ (0.307 lb/in³)
- AmesWeb, “Density of Copper and Copper Alloys”C36000 8.50 g/cm³; C11000 8.89 g/cm³
- Fisk Alloy, “C11000 ETP Copper”C110 density 8.94 g/cm³ (0.322 lb/in³)
- AZoM, “Grade 5 Ti-6Al-4V Alloy (UNS R56200)”Ti-6Al-4V density 4.43 g/cm³ (0.160 lb/in³)
- Wikipedia, “Ti-6Al-4V”Ti-6Al-4V density 4.429–4.512 g/cm³
- Wikipedia, “Nominal Pipe Size” (ASME B36.10 dimensions)Pipe outside diameters and schedule 40/80 wall thicknesses
- The Engineering ToolBox, “ANSI Steel Pipe Schedule 40”Schedule 40 dimensions and weights per foot (used as test values)
- The Engineering ToolBox, “ANSI Steel Pipes Schedule 80”Schedule 80 dimensions and weights per foot (used as test values)
- NIST Special Publication 811, Appendix B.9: conversion factorsInch, pound, ounce, gallon and fluid-ounce conversions