Cutting Guide
Metal Sheet Weight & Density Guide
Density figures for common sheet materials, and how to turn a part's dimensions into a weight for handling, shipping and material cost.
Weight matters for more than curiosity — it sets shipping cost, tells you whether a part needs two people or a hoist to lift, and multiplied by material price per kilogram gives a straightforward material cost for quoting a job.
Calculate weight for any shape
Get weight and material cost for rectangles, discs and rings cut from sheet stock.
Density by material
| Material | Density |
|---|---|
| Mild steel | 7.85 g/cm³ |
| Stainless steel | 8.00 g/cm³ |
| Aluminium | 2.70 g/cm³ |
| Brass | 8.50 g/cm³ |
| Copper | 8.96 g/cm³ |
These are standard reference figures — specific alloys and tempers vary slightly, so use a supplier's certified figure if the weight needs to be exact rather than an estimate.
Working out the weight
Weight comes from volume times density, and volume for a flat cut part is simply its area times the sheet thickness.
Worked example: a 200mm × 150mm mild steel part cut from 3mm plate has an area of 30,000mm² (300cm²) and thickness of 0.3cm, giving a volume of 90cm³. At mild steel's 7.85 g/cm³ that's about 706g per part — multiply by quantity for the whole job's weight.
Why weight matters for a cutting job
Beyond shipping and handling, weight is one of the two main components of material cost alongside sheet utilisation — see the sheet nesting guide for the other half of that equation. A job's total weight, multiplied by price per kilogram for the material, gives a straightforward material cost to add to machine time cost when quoting.
Frequently asked questions
What is the density of mild steel?
Approximately 7.85 grams per cubic centimetre (7,850 kg/m³) — the reference figure most cutting and weight calculations use.
How much lighter is aluminium than steel?
Aluminium is about 2.70 g/cm³ versus mild steel's 7.85 g/cm³ — roughly a third of the weight for the same volume.
How do I calculate the weight of a cut metal part?
Multiply the part's flat area by material thickness to get volume, then multiply by density. A 200mm x 150mm x 3mm mild steel part is about 706g.