CutMeter
Cut length from DXF: pierces, area and weight
Upload a DXF to get the total cut length, the length by layer and by object type, the number of pierces, closed contours and open chains, net area, bounding box and weight. Free, no sign-up.
Cut length is the total length of every cut line and curve in the DXF, measured along arcs and splines, and pierces are one per closed contour plus one per open chain. A 100 x 50 mm plate with one 20 mm hole has 362.83 mm of cut, 2 pierces and a net area of 4,685.84 mm², and weighs 0.110 kg in 3 mm S235JR steel.
How it is calculated
Cut length is the sum of all cut geometry in the file: lines, arcs, circles, ellipses, polylines with arc segments and splines. Arcs and splines are measured exactly along the curve, not as straight chords. Parts inside blocks are counted too, with their scale, rotation, mirroring and arrays.
Pierces are counted as one per closed contour plus one per open chain. Ends closer than the joining tolerance are treated as connected. Duplicate and overlapping lines are not counted twice.
Net area is the area of each outer contour minus the holes inside it. Weight is net area x thickness x density of the material you choose, with densities from EN standards for steel and stainless steel and from published material data for aluminium, copper and brass.
Formula
Cut length L = the sum of the lengths of all counted segments. Pierces N = closed contours + open chains. Net area A = the area of every contour at even nesting depth minus the area of every contour at odd depth (holes), with overlapping contours counted once and never below 0. Weight m = A x t x ρ / 1,000,000,000.
L in mm; A in mm²; t = sheet thickness in mm; ρ = density in kg/m³; m in kg. The nesting depth of a contour is the number of contours around it: an outer contour has depth 0, a hole depth 1, a part inside a hole depth 2.
Every outer contour needs a pierce as well as every hole, because the cut must start somewhere on each closed path. Lead-ins, lead-outs and kerf are not added: L is the length of the drawn geometry. A duplicate line counts once, and a line that partly lies on top of other cut geometry counts only for the part that is not already cut.
Example result
| Measure | Value |
|---|---|
| Outer contour | 100 x 50 mm |
| Hole diameter | 20 mm |
| Cut length | 362.83 mm |
| Net area | 4,685.84 mm² |
| Pierces | 2 |
| Material | S235JR, 3 mm |
| Weight | 0.11 kg |
Outer contour 2 x (100 + 50) = 300 mm and hole pi x 20 = 62.83 mm, so L = 362.83 mm. Two closed contours give 2 pierces. A = 100 x 50 - pi x 10² = 4,685.84 mm². In S235JR (7,850 kg/m³) at 3 mm, m = 4,685.84 x 3 x 7,850 / 10⁹ = 0.110 kg.
What counts towards cut length and pierces
| In the drawing | Cut length | Pierces |
|---|---|---|
| Closed contour (outer edge or hole) | Counted in full | 1 |
| Open chain (a path that does not close) | Counted in full | 1 |
| Line drawn twice on top of itself | Counted once | None extra |
| Line partly on top of other cut geometry | Only the part not already cut | None extra |
| Block insert | Counted with its scale, rotation, mirroring and arrays | 1 per contour or chain |
| Text, dimensions and hatching | Not counted | 0 |
| Lines on a layer named BEND, BENDLINES or BEND_LINES, or on an Inventor flat pattern layer (IV_BEND, IV_BEND_DOWN, IV_TANGENT, IV_ARC_CENTERS), in any letter case | Not counted | 0 |
Questions about measuring
Which files can I upload?
DXF files, text or binary, from version R12 to 2018, up to 20 MB. DWG is not supported - save the drawing as DXF in your CAD first.
What if my file has no units set?
We read the units from the file. If they are not set, we assume millimetres and show a notice. You can change the drawing units in Settings.
Does it count every layer?
Yes. You see the cut length in total, by layer and by object type. Text, dimensions and hatching are not counted as cuts - they are listed under Not counted.
How is the weight calculated?
Weight = net area x thickness x density. Choose the grade and thickness, for example S235JR or 1.4301 at 3 mm. Densities for steel and stainless steel follow EN standards; aluminium, copper and brass come from published material data.
What happens to my file?
It is processed on our server in the EU and deleted after 24 hours. It is not used for anything else unless you turn that on in your account.
How are pierces counted in a DXF?
One pierce per closed contour and one per open chain, so a plate with 4 holes has 5 pierces. Ends closer than the joining tolerance (0.01 mm by default) are treated as connected before contours are counted.
Does the cut length include lead-ins and kerf?
No. The cut length is the length of the geometry in the file. Lead-ins, lead-outs, micro-joints and kerf compensation are set on the machine and are not added.
How accurate is the cut length?
Lines, arcs and circles are measured exactly. Ellipses and splines are measured numerically, and the result shows the bound of the error next to the cut length.
How many parts fit on a sheet?
CutMeter gives a free estimate from the part's bounding box in a simple grid on 1,000 x 2,000, 1,250 x 2,500 or 1,500 x 3,000 mm sheets or your own size, with a gap between parts and a margin at the edge. For the 100 x 50 mm plate on a 1,250 x 2,500 mm sheet with a 5 mm gap and a 10 mm margin it gives 506 parts (22 x 23, turned by 90°). It is not a nesting.
How do I turn cut length into a price?
Multiply the cut length in metres by your price per metre and add the pierces times your price per pierce, or price by machine time. CutMeter Pro does this from your own rate card; CutMeter does not suggest rates.