Metal Weight Calculator
Calculate the weight of steel, stainless, aluminum, copper or brass stock — plate, bar or tube — from its dimensions.
How it works
Weight = cross-section area × length × density · plate/flat = W×T · round bar = π·d²÷4 · square = side² · tube = π(OD²−ID²)÷4 · steel 7.85 g/cm³
The weight of any prismatic metal stock is its constant cross-section area times its length times the material density. Getting the cross-section right for the shape is the whole game — a solid round bar uses π·d²÷4, while a tube subtracts the hollow bore. Densities vary a lot: aluminum is barely a third the weight of steel, so switching material changes the answer dramatically even when the dimensions are identical. Use it to price stock by weight, check crane and rack loads, or estimate shipping.
Worked example
A mild-steel plate 1000 mm long × 100 mm wide × 10 mm thick: cross-section = 100 × 10 = 1000 mm²; volume = 1000 × 1000 = 1,000,000 mm³ = 1000 cm³; weight = 1000 × 7.85 ÷ 1000 = 7.85 kg (about 17.3 lb).
Frequently asked questions
Which density should I use for steel?
Mild and carbon steels are about 7.85 g/cm³; stainless is slightly higher at roughly 8.0. This tool uses those values, plus aluminum 2.70, copper 8.96 and brass 8.50.
How do I weigh a hollow tube?
Choose the round-tube shape and enter both the outside and inside diameters. The calculator finds the ring-shaped cross-section π(OD² − ID²) ÷ 4, so it counts only the wall metal, not the bore.
Can I mix inches and millimetres?
Enter every dimension in millimetres for a consistent result. If you work in inches, convert first (1 in = 25.4 mm) so length and cross-section share the same unit.
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This calculator is for educational purposes. Double-check important results before acting on them.