Weight and material cost for rectangular, circular and ring parts cut from sheet — set shape, dimensions and material.
Start with the finished shape, dimensions in millimetres and sheet thickness. Choose rectangle, disc or ring, then select a material or enter a custom density. Quantity scales the batch weight. The optional price per kilogram converts that weight into a net material estimate. It does not calculate a supplier’s complete manufacturing price, and the default price is an example input rather than a market rate.
A rectangle uses width multiplied by height. A disc uses π multiplied by radius squared; a ring subtracts the inner disc area from the outer disc area. Area in mm² is divided by 100 to give cm². Multiply by thickness divided by 10 to get volume in cm³, then by density in g/cm³ and divide by 1,000 for kilograms. The calculator uses 7.85 for mild steel, 8.00 for stainless steel, 2.70 for aluminium, 8.50 for brass and 8.96 for copper. Check the actual alloy before ordering.
The default 200 × 150 × 3 mm plate has an area of 30,000 mm², or 300 cm². Its thickness is 0.3 cm, so volume is 90 cm³. At 7.85 g/cm³ it weighs 706.5 g, or 0.7065 kg. With the example £1.20/kg input, net material cost is £0.8478, displayed as £0.85. Change quantity to 25 and the batch weighs 17.6625 kg, costing £21.20 after rounding. Totals use the unrounded weight, so multiplying rounded screen values may differ slightly.
Machine rate, cutting speed by thickness, pierces and setup do not affect physical weight. They do affect the finished quote. Use the laser, plasma or waterjet cost calculator to add cutting time: path length divided by speed, plus pierce count multiplied by pierce seconds. Those tools multiply batch time by an hourly rate and add net material cost. Setup and programming still need separate allowances.
A finished part occupies more sheet than its net area once gaps, edge margins and an unusable skeleton are included. Use the sheet metal nesting guide to assess yield. A rectangle with holes needs its removed area deducted separately; this tool only subtracts a circular opening in ring mode. Thickness variation, alloy density, protective film, minimum sheet purchases and supplier handling also affect real orders. The weight and density guide explains the units. Confirm gross purchased material separately from the finished parts’ weight.
No. This calculator gives net part weight and material cost only. Machine rate, cut speed, pierces and setup belong in a separate cutting estimate.
Use the density for your specified alloy from your supplier. The presets are 7.85 g/cm³ for mild steel, 8.00 for stainless steel and 2.70 for aluminium; custom density is available.
A supplier may charge for the full sheet, a minimum quantity or the nested area including gaps and scrap. The calculator prices only the net shape entered, before VAT and delivery.