---
title: "Metal Weight Formula: Steel, Aluminum, Stainless by Profile"
description: "Weight drives shipping cost, crane planning and material budgets. One formula covers every metal profile — you only need the density."
image: "https://nestingcalc.com/og-default.png"
url: "https://nestingcalc.com/guides/metal-weight-formula/"
locale: "en"
---

# Metal Weight Formula: Steel, Aluminum, Stainless by Profile

Weight drives shipping cost, crane planning and material budgets. One formula covers every metal profile — you only need the density.

## Why weight comes first

Steel is sold by weight, cranes are rated in tonnes and trucks have legal payload limits — so before anything moves, someone multiplies volume by density. Getting the number wrong by 30% is not a rounding error: it is a truck that cannot leave the yard or a beam that cannot be lifted.

## The formula

Weight = cross-section area × length × density. For a round bar the area is π × r²; for a tube it is the outer circle minus the inner circle (π/4 × (OD² − ID²)); for sheet and plate it is simply length × width × thickness. Work in metres and kg/m³, or inches and lb/in³ — never mix the two inside one calculation.

## Metal density chart (kg/m3)

Steel is the reference point: at 7,850 kg/m3, one cubic metre of mild steel weighs 7.85 tonnes. Aluminium at 2,700 kg/m3 weighs about one third of that, copper at 8,960 kg/m3 weighs slightly more than steel, and lead at 11,340 kg/m3 is the heaviest metal on this list. The full table below lists the ten metals covered by our [Metal weight calculator](https://nestingcalc.com/metal-weight-calculator/), in both metric and imperial units.

| Metal | kg/m3 | g/cm3 | lb/ft3 | vs steel |
| --- | --- | --- | --- | --- |
| Mild steel | 7,850 | 7.85 | 490 | 1.00 |
| Stainless steel | 8,000 | 8.00 | 500 | 1.02 |
| Aluminium | 2,700 | 2.70 | 169 | 0.34 |
| Copper | 8,960 | 8.96 | 559 | 1.14 |
| Brass | 8,500 | 8.50 | 531 | 1.08 |
| Bronze | 8,800 | 8.80 | 549 | 1.12 |
| Cast iron | 7,200 | 7.20 | 449 | 0.92 |
| Zinc | 7,135 | 7.14 | 445 | 0.91 |
| Titanium | 4,500 | 4.50 | 281 | 0.57 |
| Lead | 11,340 | 11.34 | 708 | 1.44 |

## Which metal is heaviest? Which is lightest?

Lead (11,340 kg/m3) is by far the heaviest of the common engineering metals - 44% denser than steel and more than four times denser than titanium. Exotic metals aside, aluminium (2,700 kg/m3) is the lightest metal you will routinely machine or weld. The steel-to-aluminium weight ratio is roughly 2.9:1, so a steel part redesigned in aluminium loses about two thirds of its weight - exactly why automotive and aerospace builders pay the aluminium premium.

## Steel vs stainless steel vs cast iron

Stainless steel (8,000 kg/m3) is barely 2% denser than mild steel (7,850 kg/m3) - corrosion resistance comes at almost no weight penalty. Cast iron at 7,200 kg/m3 is actually lighter than steel per unit volume thanks to its graphite content, yet a cast-iron part of the same shape often ends up heavier in practice because the material needs thicker sections to reach the same strength.

## Copper, brass and bronze

Copper (8,960 kg/m3) is denser than steel, which surprises many people. Its two common alloys sit just below it: brass at 8,500 kg/m3 and bronze at 8,800 kg/m3. When a brass part feels lighter than a steel one, that is design, not physics - the part is simply made thinner, because the material itself is heavier per volume.

## Weight per metre: a quick reference

Density becomes practical when multiplied by a cross-section. A 20 mm round bar has a cross-section of 314 mm2, so one metre of it weighs 2.47 kg in steel, 2.51 kg in stainless steel, 2.81 kg in copper, 0.85 kg in aluminium and 3.56 kg in lead. Ten metres of that bar in steel is 24.7 kg - enough to plan handling and shipping. The [Metal weight calculator](https://nestingcalc.com/metal-weight-calculator/) computes any diameter, wall thickness and material combination instantly.

## Quick sanity checks

A 1 m length of 50 mm solid steel round bar weighs π × 0.025² × 7,850 ≈ 15.4 kg. A 2 × 1 m sheet of 3 mm steel plate: 2 × 1 × 0.003 × 7,850 ≈ 47 kg. If your number is far from a hand estimate like this, the units — not the metal — are usually the problem.

## Using density for material cost decisions

Multiply density by volume to get weight, then weight by price per kilogram to compare real material cost - density alone is only half the story. Aluminium at twice the price per kilo of steel can still be cheaper per part once the 2.9:1 weight ratio is applied. Run both options through the [Metal weight calculator](https://nestingcalc.com/metal-weight-calculator/) and compare total weights before ordering; the [Steel Weight Table: kg/m for Round Bar, Tube, Flat Bar and Pipe](https://nestingcalc.com/guides/steel-weight-table/) lists per-metre weights for standard bar, tube and pipe sizes.

## Skip the handbook arithmetic

The [Metal weight calculator](https://nestingcalc.com/metal-weight-calculator/) computes weight for bars, tubes, sheet, flat bar and profiles in metric or imperial, for all common metals, with the totals you need for ordering and transport.

[Metal weight calculator](https://nestingcalc.com/metal-weight-calculator/) [Open the linear cutting calculator](https://nestingcalc.com/linear-cutting-calculator/)

```json
[{"@context":"https://schema.org","@type":"Organization","@id":"https://nestingcalc.com/#organization","name":"NestingCalc","url":"https://nestingcalc.com/","description":"Free cutting optimizer & nesting calculators","logo":"https://nestingcalc.com/logo-512.png"},{"@context":"https://schema.org","@type":"WebSite","@id":"https://nestingcalc.com/#website","name":"NestingCalc","url":"https://nestingcalc.com/","inLanguage":"en","publisher":{"@id":"https://nestingcalc.com/#organization"}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"NestingCalc","item":"https://nestingcalc.com/"},{"@type":"ListItem","position":2,"name":"Guides & Articles","item":"https://nestingcalc.com/guides/"},{"@type":"ListItem","position":3,"name":"Metal Weight Formula: Steel, Aluminum, Stainless by Profile","item":"https://nestingcalc.com/guides/metal-weight-formula/"}]}]
{"@context":"https://schema.org","@type":"Article","@id":"https://nestingcalc.com/guides/metal-weight-formula/#article","mainEntityOfPage":"https://nestingcalc.com/guides/metal-weight-formula/","headline":"Metal Weight Formula: Steel, Aluminum, Stainless by Profile","description":"Weight drives shipping cost, crane planning and material budgets. One formula covers every metal profile — you only need the density.","inLanguage":"en","image":"https://nestingcalc.com/og-default.png","author":{"@id":"https://nestingcalc.com/#organization"},"publisher":{"@id":"https://nestingcalc.com/#organization"},"datePublished":"2026-08-30","dateModified":"2026-10-02"}
```