Cost per cover requires two measurements: film pulled for one accepted cover and usable length delivered by the roll. Correct theoretical yield with observed failures instead of using roll price alone.
Use these equations
Theoretical covers = verified usable length ÷ average cut length.
Yield factor = accepted covers ÷ theoretical trial cuts.
Cost per accepted cover = comparable roll-cycle cost ÷ (theoretical covers × yield factor).
Worked example
| Input | Illustrative value |
|---|---|
| Verified usable length | 300 m |
| Average cut | 0.52 m |
| Theoretical whole cuts | 576 |
| Observed yield factor | 94% |
| Expected accepted covers | 541 |
These are sample numbers, not product performance. Replace them with the buyer's pan, dispenser and trial data. If a narrow web needs two sheets, count both cuts and the seam.
Record the reason for loss
Separate short cuts, film folded onto itself, second sheets, rewraps and film left on a discarded roll. The cause determines whether to change width, cutter, handling or supplier. Use the price-normalisation guide for the input cost and the product range for candidate dimensions.
