EngineerBenchEstimating sheet and plate weight
Plate mass is the net face area multiplied by thickness and material density. Enter the rectangle's length and width, then subtract any removed area. Quantity multiplies the mass for identical plates, and the optional price per unit mass gives a material-cost estimate.
Cutouts and actual thickness
Use the total face area of through-holes and through-cutouts for removed area. A pocket that stops partway through the thickness needs a separate volume calculation. Use measured thickness when nominal stock dimensions are not accurate enough for the job.
What is included in the price
The cost result covers the entered material rate only. Cutting charges, minimum order sizes, freight, tax, and purchased stock that becomes scrap are not inferred. For a hollow section rather than a flat plate, use the tube-weight calculation.
Accounting for openings and quantity
For a uniform rectangular plate, first calculate face area, subtract the total area of through-openings, and multiply by thickness. This gives material volume before density converts it to mass. A shallow pocket is not a through-opening: subtracting its full face area would remove too much volume. Model partial-depth removal separately if it matters to the estimate.
For example, a 1 m by 0.5 m plate that is 10 mm thick contains 0.005 m³ before cutouts. At an assumed density of 7,850 kg/m³, that is 39.25 kg. Quantity multiplies finished-part mass, but purchase cost may be based on a larger stock sheet. Keep finished mass, purchased mass, and scrap allowance distinct. Check that the thickness is the measured or specified stock thickness rather than a nominal gauge designation from another system. When several plates have different thicknesses or materials, calculate each group separately and total them instead of using one unweighted average.
Formula
Mass = net face area × thickness × density × quantity.