Is this a metal weight calculator and a steel weight calculator?+
Yes. It is a metal weight calculator for steel, stainless, aluminium, copper, brass and other shop metals, and a material weight calculator when you type dimensions. Dedicated pages cover a steel weight calculator, stainless steel weight calculator, copper and brass. Switch to STEP model to weigh a CAD solid.
How is metal weight calculated?+
Weight equals volume × density. Volume comes from the shape (for example length × width × thickness for a plate, or πr²L for a round bar). Density is looked up for the selected material, or entered manually for a custom alloy.
What density is used for mild steel?+
Mild steel is calculated at 7.85 g/cm³ (7850 kg/m³), which is the value most fabrication shops and steel stockholders use for estimating plate, bar and section mass.
Can I mix millimetres and inches?+
Yes. Each dimension has its own unit (mm, cm, m, inch, feet). The calculator converts everything internally to a consistent system before applying the density, then reports weight in the unit you choose.
How accurate is the result?+
The geometry is exact for the dimensions you enter. Real parts vary with mill tolerance, coating, chamfers and actual alloy density (stainless 304 vs 316, cast vs wrought aluminium). Treat the figure as a reliable estimate, not a certified weighbridge reading.
Does this include pipe schedules?+
Use the Pipe or Tube shape and enter outside diameter and wall thickness. That covers any schedule once you know OD and WT from a pipe chart. Tube and pipe use the same hollow-cylinder formula.
Which shapes can I calculate weight from?+
Plate and sheet (including sheet metal), round bar, square bar, rectangular bar, tube, pipe, solid cylinder, disc, and a custom box. That covers bar, part and component weight from dimensions as well as a metal mass take-off.
Which materials have densities built in?+
Mild steel, carbon steel, EN8, EN19, EN24, D2, H13, stainless 304 and 316, aluminium 6061 and 7075, copper, brass, bronze, titanium, cast iron, nylon, Delrin / acetal, ABS and PVC. Enter a custom density for anything else.
What is the unit weight of steel in kg/m³?+
The unit weight of steel used here is 7850 kg/m³ (7.85 g/cm³). That is also the unit weight of mild steel. Weight of steel per cubic cm is 7.85 g; per cubic inch about 0.283 lb. Stainless is 8000 kg/m³ — do not use 7850 for 304/316.
Can I calculate weight of material in kg?+
Yes. This is an online material weight calculator and metal weight calculator in kg (switch to lb, g, oz or tonne). Calculate weight of material from plate, bar, tube or a STEP solid. Carbon steel uses the same 7.85 g/cm³ as mild steel.
Can I weigh a STEP or STP file?+
Yes. The dedicated STEP model weight calculator opens a .STEP / .STP solid, tessellates it in your browser, and multiplies volume by density. You can also switch to STEP model on this page. Click two points on the 3D view to check a dimension. Treat the mass as a quotation estimate, not a certified scale reading.
How accurate is the weight from a STEP file?+
Volume comes from the tessellated triangle mesh (closed solids from Open CASCADE), then multiplied by density. Fine fillets and coarse tessellation change the last few percent. Confirm certified shipping weights on a scale.