Plate Weight Calculator
Calculate the weight of a steel, aluminium, stainless or plastic plate from its dimensions — rectangular sheet, round disc or ring — with 24 built-in material densities, a quantity multiplier, surface area, and results in both kg and lb.
Input
Applies to every dimension and density below. Results are always reported in both systems.
mm in metric, inches in imperial.
mm in metric, inches in imperial.
Sets the density. Pick Custom to enter a value from your own material data sheet.
Number of identical pieces — adds a total-weight row for the whole order.
Output
| Metric | Value |
|---|---|
| No data yet | |
Guides
Work out how much a plate weighs before it arrives on a truck. Enter the dimensions, pick a material, and get the weight per piece, the total for the whole order, the volume, the weight force, and the surface area — in kilograms and pounds at the same time.
Handles rectangular sheet, round disc, and ring (a disc with a hole cut out), with 24 built-in densities covering carbon and stainless steels, aluminium alloys, copper, brass, bronze, titanium, and common plastics.
How to use it
- Pick your unit system — metric (mm, kg/m³) or imperial (inch, lb/ft³).
- Choose the shape. Rectangular plate needs a length and width; a disc needs an outside diameter; a ring needs both an outside and a hole diameter.
- Enter the thickness.
- Choose the material — that sets the density. Pick Custom to type a density straight off a data sheet.
- Set the quantity if you're pricing more than one piece; a total-weight row appears for the whole batch.
How the weight is calculated
Weight is just volume times density:
mass = face area × thickness × density
Face area is length × width for a rectangle, π/4 × d² for a disc, and π/4 × (D² − d²) for a ring. The calculator does the unit bookkeeping so you never have to convert mm³ into m³ by hand.
Which density should I use?
Use the value in the material's data sheet if you have one — alloy families vary by a percent or two, and that matters on a multi-tonne order. The built-in figures are standard handbook values: 7,850 kg/m³ for carbon steel, 8,000 for austenitic stainless (304/316), 2,700 for aluminium 6061. Where a mill's certificate disagrees with the list, trust the certificate and use Custom.
Why does it show surface area?
Because it's what you need to quote coating. The figure covers both faces plus the edge band, so it feeds straight into paint coverage, galvanizing, powder-coat, or passivation costs. On thin sheet the edges are negligible; on 50 mm plate they aren't.
What about mass versus weight force?
Kilograms and pounds are mass. The weight force row converts that to newtons (and pounds-force) at standard gravity — the number you want when sizing a lifting eye, a shelf bracket, or a crane sling, rather than filling in a shipping manifest.
Limits
This is a nominal calculation from stated dimensions. Real plate comes with rolling tolerances on thickness, so the delivered weight can differ by a few percent — mill certificates and theoretical weight rarely agree exactly. Also note it assumes a solid plate: subtract any cut-outs or drilled holes yourself, or model a single central hole using the ring shape.
Privacy
Everything runs in your browser — no dimensions or job data leave your machine.
Related tools
For springs made from the same stock, see the Spring Rate Calculator. If you need how much the plate grows when it heats up, use the Thermal Expansion Calculator, and for bolting it down, the Bolt Torque Calculator.