The purchasing question
Sheet purchasing depends on the approved number of blanks per sheet. An area ratio can suggest a theoretical maximum but cannot establish a valid die-cut layout. Start from a supplier-confirmed layout yield, then add a clearly defined process allowance.
Calculation method
Gross sheets = good boxes ÷ boxes per sheet ÷ usable fraction. Round the result up to a whole sheet. If the supplier sells fixed bundles, round that sheet count to a complete bundle separately. The second rounding is stock, not an additional process scrap percentage.
Worked example
For 10,000 accepted boxes, four blanks per sheet and 5% gross-input waste, the estimate is 10,000 ÷ 4 ÷ 0.95 = 2,631.5789 sheets. Purchase at least 2,632 sheets before bundle constraints. At €2 per sheet, the sheet subtotal is €5,264, or €526.40 per thousand target boxes.
The calculation assumes the stated average usable fraction and layout apply to the order. Fixed setup sheets may need an additional explicit allowance. If a revised layout increases yield, verify that printing direction, die spacing and machine constraints still permit it.
Checks before using the result
- Use confirmed whole blanks per sheet.
- Round sheet count up after applying waste.
- List bundle surplus separately from expected process loss.
Common questions
Should the waste rate be added to the box count?
For a gross-input waste rate, divide the net sheet need by the usable fraction. A simple percentage markup uses a different convention.