Aluminum Weight Calculator
Weigh aluminum stock before you buy or ship it. Pick a shape — plate/sheet, round bar, round tube, or square bar — enter dimensions in inches, choose the alloy, and get pounds and kilograms per piece and total.
Example: with Shape Plate / sheet (thickness × width × length) · Thickness or wall (in) 0.25 · Width or side (in) 12 · Diameter / OD (in) 2 · Length (in) 48 → Total weight: 14.04 lb.
- In kilograms6.37 kg
- Per piece14.04 lb each (144.0 cu in)
Computed by the calculator below using its default values. Change any input to see your own numbers.
Weight = volume × density. Wrought aluminum alloys run 2.68–2.81 g/cm3 (0.097–0.102 lb per cubic inch) — about one third the density of steel.
How aluminum weight is calculated
Every metal weight calculation is volume times density. For plate that is thickness × width × length; for round bar, π/4 × diameter² × length; for tube, the same formula minus the bore. Multiply cubic inches by the alloy's density in pounds per cubic inch and you have the piece weight.
Alloy choice barely moves the number: common wrought alloys span 2.68 g/cm3 (5052) to 2.81 (7075), a 5% spread. The default, 6061 at 2.70 g/cm3 (0.0975 lb/in3), is the general-purpose alloy for plate, bar, and structural shapes. For quick estimates, remember that aluminum weighs about 35% as much as the same volume of steel — the reason it dominates aircraft, truck bodies, and anything you have to lift.
How it’s calculated
Volume in cubic inches: plate = t × w × L; round bar = π/4 × d² × L; round tube = π/4 × (OD² − ID²) × L with ID = OD − 2 × wall; square bar = side² × L. Weight = volume × density, using typical published alloy densities (Aluminum Association figures): 6061 0.0975 lb/in3, 7075 0.1015, 5052 0.0968, 3003 0.0986, 2024 0.1004. Kilograms at 1 lb = 0.45359237 kg.
Assumes solid, nominal dimensions — mill tolerance, anodizing, and cut kerf change real weight by a percent or two.
Handy aluminum weights (6061)
| Stock | Size | Weight |
|---|---|---|
| Sheet, 1/8 in | 4 × 8 ft sheet | ≈ 56 lb |
| Plate, 1/4 in | 12 × 48 in | ≈ 14.0 lb |
| Round bar, 1 in | per ft | ≈ 0.92 lb |
| Round bar, 2 in | per ft | ≈ 3.68 lb |
| Square bar, 1 in | per ft | ≈ 1.17 lb |
| Tube, 2 in OD × 1/4 wall | per ft | ≈ 1.61 lb |
Computed with volume × 0.0975 lb/in3 (6061); rounded.
Common mistakes
- Using the steel density by habit — steel is 0.283 lb/in3, almost 3× aluminum, so the error is huge.
- Measuring tube wall as inside diameter: ID = OD − 2 × wall, and swapping them can make the bore negative.
- Mixing feet and inches in one entry — this tool takes every dimension in inches.
- Forgetting quantity when estimating freight: 40 pieces of 14 lb plate is 560 lb, a different shipping class.
Frequently asked questions
What is the formula for aluminum weight?
Weight = volume × density. In inches: plate weight (lb) = thickness × width × length × 0.0975 for 6061. A 1/4 in × 12 in × 48 in plate is 144 cubic inches × 0.0975 = 14.04 lb.
How much does aluminum weigh per cubic inch?
About 0.0975 lb per cubic inch for 6061 (2.70 g/cm3). Alloys range from 0.0968 (5052) to 0.1015 (7075) — within about 5% of each other.
How much lighter is aluminum than steel?
Roughly 65% lighter. Steel is about 0.283 lb/in3 versus 0.0975 for aluminum, so an identical part in aluminum weighs a bit over one third as much.
Does the alloy really change the weight?
Only slightly. Switching 6061 to 7075 adds about 4% weight; 5052 saves under 1%. Pick alloy for strength and corrosion behavior — the weight difference rarely decides anything.
How do I weigh a 4 × 8 sheet?
Convert to inches (48 × 96), multiply by thickness, then by 0.0975. A 1/8 in sheet: 48 × 96 × 0.125 = 576 cubic inches ≈ 56 lb.