Aluminum Weight Calculator
Calculate the weight of aluminum shapes by alloy, with comparison to steel equivalent weight. See also our Metal Weight Calculator, Steel Weight Calculator, and Pipe Weight Calculator.
Shape & Alloy
Dimensions
How to Use the Aluminum Weight Calculator
Select the aluminum shape, choose the alloy grade, enter the total length, and provide cross-section dimensions. The calculator computes weight per foot, total weight, the equivalent weight if the same part were made from steel, and the percentage weight savings. This comparison helps engineers and fabricators evaluate material substitution decisions for weight-critical applications.
Formula
Weight = Cross-Section Area × Length × Density
Aluminum 6061 Density = 0.0975 lbs/in³ (169 lbs/ft³)
Weight Savings vs Steel = (1 - Al Density / Steel Density) × 100%
Plate Area = Width × Thickness
Round Bar Area = π × (D/2)²
Tube Area = π × ((OD/2)² - ((OD-2t)/2)²)
Example Calculation
6061-T6 Aluminum Plate: 4" × 0.25" × 96" (8 ft)
Area = 4 × 0.25 = 1.0 in²
Weight/ft = 1.0 × 0.0975 × 12 = 1.17 lbs/ft
Total Weight = 1.0 × 0.0975 × 96 = 9.36 lbs
Steel Equivalent = 1.0 × 0.2836 × 96 = 27.23 lbs
Weight Savings = (1 - 9.36/27.23) × 100 = 65.6%
Reference Table — Aluminum Alloy Properties
| Alloy | Density (lbs/in³) | Yield Strength (ksi) | Best Application |
|---|---|---|---|
| 6061-T6 | 0.0975 | 40 | General structural, frames |
| 6063-T5 | 0.0970 | 21 | Extrusions, architectural |
| 7075-T6 | 0.1010 | 73 | Aerospace, high-stress parts |
| 2024-T3 | 0.1000 | 50 | Aircraft structures, fatigue |
| 5052-H32 | 0.0968 | 28 | Marine, chemical tanks |
| 3003-H14 | 0.0986 | 21 | Sheet metal, HVAC ducts |
| 5083-H116 | 0.0960 | 33 | Shipbuilding, pressure vessels |
Frequently Asked Questions
How much lighter is aluminum than steel?
Aluminum is approximately 65% lighter than steel by volume. A part made from 6061 aluminum weighs about one-third of the same part in carbon steel. However, aluminum has lower strength, so thicker sections may be needed, reducing the net weight savings to 40-50% in structural applications.
What is the most common aluminum alloy?
6061-T6 is the most widely used aluminum alloy for structural applications. It offers good strength (40 ksi yield), excellent corrosion resistance, good weldability, and is available in all common shapes. It's the "A36 of aluminum" — the default choice for most projects.
What is the difference between 6061 and 7075 aluminum?
7075-T6 is nearly twice as strong as 6061-T6 (73 ksi vs 40 ksi yield) but costs 3-4x more, is harder to weld, and has lower corrosion resistance. 7075 is used in aerospace and high-performance applications where strength-to-weight ratio is critical.
Can aluminum replace steel in structural applications?
Yes, but the section must be redesigned. Aluminum's modulus of elasticity is one-third of steel's, so deflection often controls the design. Aluminum members typically need to be 1.5-2x deeper than steel equivalents to achieve similar stiffness, though they'll still be lighter overall.
How much does aluminum cost compared to steel?
Aluminum typically costs 2-3x more per pound than carbon steel. However, since aluminum is 65% lighter, the cost per linear foot is often only 30-50% more than steel. For weight-sensitive applications, the total project cost may be lower due to reduced foundation and handling requirements.
Which aluminum alloy is best for marine use?
5052-H32 and 5083-H116 are the preferred marine alloys due to their excellent saltwater corrosion resistance. 6061 can also be used with proper anodizing or coating. Never use 2024 or 7075 in marine environments — they are highly susceptible to stress corrosion cracking in saltwater.