Folding carton sheet utilisation calculator
Work out how many blanks fit a sheet in either orientation, how many sheets an order needs, and how much board is wasted.
Board is usually the largest single cost in a folding carton job, so how well a blank fits the sheet decides the price more than anything happening on the press.
This compares both orientations, picks the better one, and shows what proportion of the sheet ends up as product rather than waste.
Calculator
How to use it
- Enter Sheet width in mm
- Enter Sheet height in mm
- Enter Gripper and trim in mm. Total unusable margin across the sheet
- Enter Blank width in mm. Flat blank, not the finished carton
- Enter Blank height in mm
- Enter Cartons required in pieces
- Enter Waste allowance in %
Formula
Worked example
A 720 x 1020 mm sheet with 12 mm gripper and trim, running a 210 x 297 mm blank:
- Usable sheet = 708 x 1008 mm
- Upright = floor(708/210) x floor(1008/297) = 3 x 3 =
9 up - Rotated = floor(708/297) x floor(1008/210) = 2 x 4 =
8 up - Best is 9 up, utilisation = (9 x 62,370) / 734,400 =
76.4%
Assumptions
- Blanks are placed in a simple grid in one orientation. Mixed orientation and nested layouts can fit more and are not modelled here.
- Gripper and trim is taken off both dimensions as a single total margin.
- Blank dimensions are the flat blank including all flaps, not the finished carton size.
Limitations
Every calculator on this site gives a planning figure, not a production guarantee. Check the result against your own records before committing material or money to it.
- A real imposition considers die construction, bridge and rule spacing, stripping, board grain direction and how the job will be folded and glued.
- Grain direction often forces the orientation with the lower number up, for good structural reasons.
- Utilisation here is area only. It does not value the offcut, which may be usable elsewhere.
Common mistakes
- Entering the finished carton size instead of the flat blank, which overstates how many fit.
- Ignoring grain direction and planning around the better fitting orientation that the job cannot actually use.
- Treating utilisation as a target in itself. A slightly worse fit on a cheaper sheet size is often the better job.
Frequently asked questions
How do I calculate number up on a sheet?
Divide the usable sheet dimensions by the blank dimensions, round each down, and multiply. Repeat with the blank rotated 90 degrees and take whichever gives more, subject to grain direction.
What is a good board utilisation?
It depends entirely on the blank shape and available sheet sizes. The useful exercise is comparing sheet sizes for the same blank rather than chasing a universal percentage.
Does grain direction matter?
Yes. Grain affects folding, cracking and panel stiffness, and it frequently decides the orientation regardless of which one fits better on paper.