The density of aluminum is one of its most important physical properties—and one that defines its unique advantages in modern manufacturing.

With a typical density of 2.70 g/cm³ (or 0.0975 lb/in³), aluminum stands out as a lightweight yet strong metal that’s indispensable across industries. But density isn’t just a number—it directly impacts material selection, design efficiency, transportation costs, and overall product performance.

Why is this so crucial? Because engineers and manufacturers must carefully weigh density when choosing between metals like steel, titanium, or aluminum. For example, in aerospace or automotive design, where every gram counts, aluminum’s low density can significantly reduce fuel consumption without sacrificing strength. And when it comes to aluminum alloys—such as 6061, 7075, or 5052—even small changes in composition can affect density and therefore how the material performs in specific applications.

This quick guide will explore the fundamentals of aluminum density, compare it with other metals, and outline how different alloy compositions influence performance. Whether you’re an engineer optimizing material specs or a buyer sourcing cost-effective components, understanding aluminum’s density will help you make smarter decisions.

What Is the Density of Aluminum?

The density of aluminum is the measure of its mass per unit volume. For pure aluminum, the accepted value is 2.70 g/cm³, which equals 0.0975 lb/in³ or 2700 kg/m³. This relatively low density is one of the main reasons aluminum is chosen for lightweight engineering and industrial applications.

Standard Values of Pure Aluminum

These values are used as a benchmark when comparing alloys and alternative metals.

Why Density Matters

Density affects not only how heavy a component will be, but also how it performs in relation to strength and efficiency. In aerospace, automotive, and construction industries, using aluminum instead of denser metals such as steel can significantly reduce overall weight without compromising structural integrity.

Atomic Structure and Lightweight Advantage

Aluminum’s low density comes from its face-centered cubic (FCC) atomic structure, which packs atoms efficiently while keeping the overall weight lower than many other metals. This balance of lightness and strength is why aluminum is so valued in both high-performance and everyday applications.

Aluminum Alloys and Their Densities

Aluminum alloys are divided into two main categories: wrought alloys (rolled, extruded, or forged) and casting alloys (molded into shape). Within these, there are multiple series (1xxx through 8xxx) and many specialty grades designed for unique performance requirements.

Wrought Alloys (Rolled, Extruded, Forged)

1xxx Series – Essentially Pure Aluminum

• 1100: 2.71 g/cm³ (0.098 lb/in³) – Roofing, siding, chemical equipment.
• 1350: 2.70 g/cm³ – Electrical conductors, transformers (high conductivity).

2xxx Series – Aluminum-Copper Alloys

• 2024: 2.78 g/cm³ (0.100 lb/in³) – Aerospace structures, auto components.
• 2219: 2.84 g/cm³ (0.103 lb/in³) – High-temperature aerospace parts, fuel tanks.
• 2618: 2.80 g/cm³ (0.101 lb/in³) – High-strength, used in aerospace engines and motorsports.

3xxx Series – Aluminum-Manganese Alloys

• 3003: 2.73 g/cm³ (0.099 lb/in³) – Roofing panels, siding, utensils.
• 3105: 2.72 g/cm³ (0.098 lb/in³) – Building sheets, beverage closures.

4xxx Series – Aluminum-Silicon Alloys

• 4032: 2.68 g/cm³ (0.097 lb/in³) – Automotive engine components, pistons.
• 4045: 2.70 g/cm³ – Cladding alloy, heat exchangers.

5xxx Series – Aluminum-Magnesium Alloys

• 5052: 2.68 g/cm³ (0.097 lb/in³) – Marine environments, fuel tanks.
• 5083: 2.66 g/cm³ (0.096 lb/in³) – Shipbuilding, cryogenic tanks.
• 5754: 2.67 g/cm³ (0.097 lb/in³) – Automotive body panels, marine.

6xxx Series – Aluminum-Magnesium-Silicon Alloys

• 6061: 2.70 g/cm³ (0.0975 lb/in³) – Aerospace, pipelines, automotive.
• 6082: 2.70 g/cm³ – Bridges, cranes, transport applications.
• 6463: 2.69 g/cm³ – Architectural applications, decorative trims.

7xxx Series – Aluminum-Zinc Alloys

• 7075: 2.81 g/cm³ (0.102 lb/in³) – Aircraft, defense, sporting goods.
• 7475: 2.80 g/cm³ – Aerospace structural parts.
• 7050: 2.83 g/cm³ – High toughness, aerospace wing and fuselage components.

8xxx Series – Miscellaneous Alloys

• 8011: 2.71 g/cm³ – Foil, packaging, bottle caps.
• 8090 (Al-Li alloy): 2.55 g/cm³ – Aerospace lightweight structures.

Casting Alloys

A3xx.x Series – Aluminum-Silicon-Copper

• A356: 2.68 g/cm³ – Automotive wheels, aerospace castings.
• 319: 2.75 g/cm³ – Engine blocks, housings.

5xx.x Series – Aluminum-Magnesium

• 535: 2.65 g/cm³ – Marine castings, corrosion-resistant parts.

7xx.x Series – Aluminum-Zinc

• 707: 2.80 g/cm³ – High-strength aerospace castings.

Specialty and Aerospace Alloys

• Al-Li Alloys (8090, 2195): 2.50–2.55 g/cm³ – Very low density, used in space applications.
• 6069: 2.70 g/cm³ – Automotive crash-resistant alloy.
• 2219-T87: 2.84 g/cm³ – NASA rocket fuel tanks.
• 2618A: 2.80 g/cm³ – Aircraft engine parts, motorsport pistons.

Comprehensive Density Reference Table

Aluminum Density vs. Other Metals

One of the main reasons aluminum is so widely used is its favorable density compared to other engineering metals. By being significantly lighter, aluminum allows manufacturers to reduce weight while maintaining adequate strength. This balance is especially important in aerospace, automotive, and construction.

Aluminum vs. Steel

• Steel Density: ~7.85 g/cm³ (0.284 lb/in³)
• Aluminum Density: 2.70 g/cm³ (0.0975 lb/in³)
• Steel is nearly three times denser than aluminum.
• Substituting aluminum for steel in structural parts can reduce weight by up to 65%, improving fuel efficiency and handling in vehicles and aircraft.

Aluminum vs. Titanium

• Titanium Density: ~4.50 g/cm³ (0.163 lb/in³)
• Titanium is denser than aluminum but offers higher strength.
• Aluminum is preferred when lightweight and cost-efficiency are priorities, while titanium is chosen for extreme strength-to-weight in aerospace and medical implants.

Aluminum vs. Copper

• Copper Density: ~8.96 g/cm³ (0.324 lb/in³)
• Copper is more than three times denser than aluminum.
• Aluminum is often used in place of copper in electrical applications, such as transmission lines, because it is lighter and less expensive while still offering good conductivity.

Aluminum vs. Magnesium

• Magnesium Density: ~1.74 g/cm³ (0.063 lb/in³)
• Magnesium is lighter than aluminum but less strong and more prone to corrosion.
• Aluminum strikes a better balance between strength, corrosion resistance, and cost, which makes it more widely used.

Quick Comparison Table

Conclusion: Why Understanding Aluminum Density Matters

The density of aluminum—around 2.70 g/cm³ for pure grades and slightly higher for certain alloys—is one of the key reasons this metal remains so essential across industries. Its unique balance of lightweight performance, strength, and versatility makes it the go-to choice for aerospace, automotive, construction, and countless other applications.

By understanding how density varies across aluminum alloys and how it compares with other metals, engineers and buyers can make smarter, more cost-effective, and more sustainable material decisions.