How to use the metal weight calculator
Three inputs, one click. Have a 3D model? Upload the STEP file to Komacut instead: the platform returns the exact part weight, holes and cut-outs included, with a price.
Pick the shape
Sheet or plate for anything flat, round bar for solid rod, rectangular bar for flat bar and block stock.
Choose the material grade
The list matches the grades stocked at Komacut's factories: SPCC and SAPH440 cold rolled steel, Q235, Q355 and #20 hot rolled steel, 65Mn, SGCC, SS301/304/316 stainless, and AL1060, AL5052, AL6061, AL6063 and AL7075 aluminium.
Enter dimensions and quantity
Switch between millimetres and inches with the unit toggle. Press Calculate weight to get the unit and total weight in both kg and lb.
How metal weight is calculated
The weight of a solid metal part is its volume multiplied by the density of the material. The only thing that changes by shape is how the volume is found.
Worked examples
Density of common sheet metal materials
The calculator uses the nominal densities in this table. Within a family, density barely moves: every carbon steel grade Komacut stocks is about 7,850 kg/m³, so switching from Q235 to Q355 for strength doesn't change the part weight.
Stainless is about 2% heavier than carbon steel. Aluminium alloys are roughly a third of steel.
| Material | Komacut grades | kg/m³ | g/cm³ | lb/in³ |
|---|---|---|---|---|
| Carbon steel, cold rolled | SPCC, SAPH440 | 7,850 | 7.85 | 0.284 |
| Carbon steel, hot rolled | Q235, Q355, #20 | 7,850 | 7.85 | 0.284 |
| Spring steel | 65Mn | 7,850* | 7.85 | 0.284 |
| Galvanized steel | SGCC | 7,850† | 7.85 | 0.284 |
| Stainless steel (austenitic) | SS301, SS304, SS316 | 8,000 | 8.00 | 0.289 |
| Aluminium 1000 series | AL1060 | 2,705* | 2.71 | 0.098 |
| Aluminium 5000 series | AL5052 H32 | 2,680* | 2.68 | 0.097 |
| Aluminium 6000 series | AL6061 T6, AL6063 T5 | 2,700 | 2.70 | 0.098 |
| Aluminium 7000 series | AL7075 T6 | 2,810* | 2.81 | 0.102 |
* Nominal handbook value, pending confirmation. † Base steel density; the zinc coating is not included.
Why part weight matters in sheet metal fabrication
Material cost
Weight multiplied by the price per kilo of the raw material gives the material-cost floor of a part, and shows quickly whether a thinner gauge or a change of alloy moves the price.
Freight
Carriers charge on actual weight or volumetric weight, whichever is greater. You need the actual weight to know which applies. Komacut's packaging calculator on this hub covers the volumetric side.
Material comparison
The same part in SPCC, SS304 and AL5052 weighs 7.85 kg, 8.00 kg and 2.68 kg per 1,000 × 500 × 2 mm blank. Switching material in the dropdown shows the difference without re-modelling the part.
Sheet metal gauge to thickness reference
Komacut's China facility works in millimetres; the Mexico facility stocks imperial gauges. If your drawing is in gauge, convert to millimetres before entering it.
Values follow the Manufacturers' Standard Gauge for sheet steel. Aluminium gauge numbers use a different scale, so for aluminium enter the thickness in mm or inches directly.
| Gauge (steel) | Inches | mm | 1 m² steel |
|---|---|---|---|
| 20 ga | 0.0359 | 0.91 | 7.2 kg |
| 18 ga | 0.0478 | 1.21 | 9.5 kg |
| 16 ga | 0.0598 | 1.52 | 11.9 kg |
| 14 ga | 0.0747 | 1.90 | 14.9 kg |
| 12 ga | 0.1046 | 2.66 | 20.9 kg |
| 11 ga | 0.1196 | 3.04 | 23.8 kg |
| 10 ga | 0.1345 | 3.42 | 26.8 kg |
Frequently asked questions
How do I calculate the weight of a steel plate?
Multiply length × width × thickness to get the volume, then multiply by the density of steel, 7,850 kg/m³. A 1 m × 1 m × 10 mm plate has a volume of 0.01 m³ and weighs 78.5 kg. The calculator above does the unit conversion and shows the result in kg and lb.
Does the calculator account for holes, cut-outs and bends?
No. It calculates the weight of the solid blank. Bends don't change weight, but every hole, slot and cut-out removes material. For a formed part with features, upload the STEP file to Komacut: the platform reads the 3D geometry and returns the exact finished weight with the quote.
Why is my 304 stainless part heavier than the same part in mild steel?
Austenitic stainless steels such as SS304 and SS316 have a density of about 8,000 kg/m³ against 7,850 kg/m³ for carbon steel, so an identical part is roughly 2% heavier in stainless.
What's the difference between sheet and plate?
It's a thickness convention, not a different formula. Sheet is generally material under about 6 mm; plate is thicker. The calculator treats both the same way. Komacut laser cuts sheet and plate up to 20 mm thick.
Which aluminium alloy is the lightest?
The differences are small. AL5052 is about 2,680 kg/m³ and AL7075 about 2,810 kg/m³, a spread of under 5%. Choose an aluminium grade on strength, formability and finish, not on weight. Note that AL6061 T6 starts to crack when bent past 120°.
How accurate is the result?
The calculator uses nominal density values. The real part varies slightly with mill composition and the thickness tolerance of the raw sheet (Komacut: ±0.05 mm on 0.5–2.0 mm material).