Roofing, Siding & Exterior Building Products worked example

Scrap Trim Cost at 6.9% length lost to edge trim & offcuts: a worked example

What does the result look like when length lost to edge trim & offcuts reaches 6.9%? The full calculation is worked below with real intermediate numbers. A roll-forming supervisor uses it to quantify the dollar value of edge trim, end cuts, and offcut drops on a coil run of standing-seam or lap siding.

The inputs for this scenario

  • Coil feet run through the line: 5,000 linear ft (unchanged)
  • Material cost per foot: 1.4 $/ft (unchanged)
  • Length lost to edge trim & offcuts: 6.9 % (raised for this scenario; the documented default is 6)
  • Scrap haul-off & handling: 75 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Total scrap trim cost = coil feet x cost per foot x scrap rate + haul-off) to the inputs above produces each figure below.
  • At this operating point the engine returns 558 $ for total scrap trim cost, the number this scenario is built around.
  • At this operating point the engine returns 0.11 $ / piece for scrap trim cost per unit.
  • At this operating point the engine returns 483 $ for variable scrap trim cost.
  • At this operating point the engine returns 75 $ for fixed scrap trim cost adder.

How this compares with the baseline

  • Against the tool's baseline example, where length lost to edge trim & offcuts sits at 6% and the headline result is 495 $, this scenario comes in 12.73% above the baseline at 558 $.
  • A figure at this level is achievable when length lost to edge trim & offcuts is genuinely sustained, not just peaked for a shift. It treats the trim scrap rate as a flat percentage; real trim loss varies with coil width, gauge, and how many profiles nest across the strip.

Results at a glance

  • Total scrap trim cost: 558 $ (headline result)
  • Scrap trim cost per unit: 0.11 $ / piece
  • Variable scrap trim cost: 483 $
  • Fixed scrap trim cost adder: 75 $

Run it with your numbers

  • Every input above is editable in the live Scrap Trim Cost calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.