Estimate the weight of common solid and hollow aluminum shapes from their dimensions, quantity, and material density.
Aluminum weight is calculated from cross-sectional area, length, quantity, and alloy density. Hollow shapes subtract the interior void from the exterior area before volume is determined.
How to Use This Calculator
- Select the correct solid or hollow shape.
- Enter exterior dimensions and wall thickness where required.
- Enter length, whole-piece quantity, and alloy density.
- Calculate and review weight, volume, and area.
After a successful calculation, the inputs and result remain saved in this browser. Select Reset to clear the stored values and restore the calculator defaults.
How the Aluminum Weight Calculator Works
Dimensions are converted from cubic millimeters to cubic metres before density in kg/m³ is applied. Keep full precision through the geometry calculation and round only the displayed result.
The primary relationship is Weight = cross-sectional area × length × quantity × density. Calculations retain full available precision internally; displayed values are rounded for readability.
Formula Variables and Input Guide
Select the shape, enter external dimensions and wall thickness where applicable, then supply length, quantity, and alloy density.
| Variable or term | Meaning | Unit or note |
|---|---|---|
| A | Cross-sectional area | mm² |
| L | Length | mm |
| V | Material volume | m³ |
| ρ | Alloy density | kg/m³ |
| q | Quantity | whole pieces |
Choosing the Right Inputs
Select the cross-section that matches the stock: plate or rectangular bar, solid round, round tube, or rectangular tube. Enter finished dimensions in millimetres, physical length in millimetres, and a whole-piece quantity. For hollow shapes, wall thickness must leave a positive interior dimension on every side.
Use the density for the specified alloy and temper when available instead of assuming every aluminum product is exactly 2,700 kg/m³. Nominal tube sizes, corner radii, extrusion webs, holes, coatings, and mill tolerances can change actual material volume. For purchasing or shipping, compare the model with supplier weight-per-length data when it is provided.
Practical Uses
- Estimating material purchase and shipping weight.
- Comparing solid and hollow aluminum profiles.
- Checking CAD or fabrication takeoffs.
- Calculating approximate weight per metre of stock.
Cross-sectional formulas
| Shape | Area formula |
|---|---|
| Plate or rectangular bar | width × thickness |
| Solid round bar | πd² ÷ 4 |
| Round tube | π[D² − (D − 2t)²] ÷ 4 |
| Rectangular tube | WH − (W − 2t)(H − 2t) |
Understanding Your Results
Total weight is shown in kilograms and pounds, with calculated material volume and cross-sectional area.
The common 2,700 kg/m³ density is a general approximation. Use the alloy datasheet when procurement, shipping, or structural calculations need tighter accuracy.
Worked Example
A 100 × 5 mm plate, 1,000 mm long, has 0.0005 m³ volume and weighs about 1.35 kg at 2,700 kg/m³.
A 50 mm outside-diameter tube with a 3 mm wall has an inside diameter of 44 mm. Its cross-section is π(50² − 44²) ÷ 4 ≈ 442.96 mm² before length and density are applied.
Checking the Result by Hand
Recalculate cross-sectional area from the selected geometry, multiply by length and quantity to obtain mm³, and divide by 1,000,000,000 to obtain m³. Multiplying m³ by kg/m³ should then reproduce kilograms. Convert kilograms to pounds with 1 kg = 2.20462262185 lb.
For hollow stock, compute the outside area and subtract the inside area; the result must be positive and smaller than the solid outside section. Setting length to 1,000 mm and quantity to one gives a convenient kg-per-metre value to compare with a supplier table.
Common Mistakes to Avoid
- Subtracting wall thickness only once from diameter.
- Entering a wall thicker than the available radius.
- Using a fractional quantity.
- Ignoring corner radii, cutouts, coatings, or manufacturing tolerances.
Assumptions and Limitations
2,700 kg/m³ is a general aluminum estimate. Alloy, temper, manufacturing tolerance, rounded corners, coatings, and cutouts change actual weight.
Frequently Asked Questions
Which density should I use?
Use the specified alloy density; 2,700 kg/m³ is only a general approximation.
Is wall thickness entered once or twice?
Enter the physical wall once; the formula removes it from both sides of the section.
Does this include holes or cutouts?
Only the explicitly modeled hollow section is removed.
Can this estimate weight per metre?
Set length to 1,000 mm and quantity to one.