Cutting Guide
Sheet Metal Nesting Guide
How parts get laid out on a sheet, what limits how many fit, and simple changes that raise material utilisation and cut fewer sheets.
Nesting is simply the layout of parts on a sheet before cutting. Get it wrong and a job that should need three sheets needs four — get it right and material cost drops directly, since offcut is either scrapped or sold back at a fraction of its value.
Try your own layout
Enter your part and sheet size in the main calculator to see parts per sheet and material utilisation instantly.
The basic grid method
For a rectangular part, the simplest reliable nesting method is a grid: work out how many part-widths (plus the gap between parts) fit across the sheet's usable width, and how many part-heights fit down its usable height, then multiply. The usable area is the full sheet minus an edge margin on every side, needed for clamping and to keep the cutting head away from the sheet's edge.
Always test both orientations
Rotating the part 90 degrees changes how it interacts with the sheet's own aspect ratio, and it's common for the rotated layout to fit noticeably more parts than the "natural" orientation — especially when a part's proportions are close to the sheet's proportions. Run the grid calculation both ways and keep whichever gives more parts per sheet.
Gap and edge margin
The gap between parts needs to be at least the kerf width of your cutting process — see the kerf width guide — plus a small safety allowance so heat from one cut doesn't distort a neighbouring part before it's cut free. Edge margin is set by your machine's clamping and travel limits rather than the cutting process itself, and is usually a fixed figure for a given machine.
Material utilisation
Material utilisation is the share of the sheet that ends up as parts rather than offcut: total part area divided by sheet area, as a percentage. It's a useful single number for comparing layouts or sheet sizes — a smaller sheet with a tighter fit can sometimes out-perform a larger sheet with more wasted margin, especially for small orders.
For weighing up the actual material cost of that offcut, see the metal sheet weight & density guide.
Frequently asked questions
How do you calculate parts per sheet?
Work out how many part widths (plus gap) fit across the usable sheet width and how many part heights fit down the usable height, then multiply columns by rows. Test the rotated orientation too and keep whichever fits more.
What is material utilisation in sheet cutting?
The percentage of a sheet's area that becomes finished parts rather than offcut — total part area divided by sheet area. Higher utilisation means less wasted material and fewer sheets for the same order.
Does rotating parts improve nesting?
Often, yes — a rectangular part's fit changes with orientation relative to the sheet's own proportions, so it's standard practice to check both and keep the better result.