How it is calculated
A compressed pack is often labelled with the volume after it has been opened out. Use the volume printed on the pack, not the product of the carton sizes, when the maker states it that way.
Packs = round up(area × thickness / pack volume)
Where the numbers come from
- Area — unit in the field: m²
- Thickness — unit in the field: mm
- Pack volume — unit in the field: m³
Example
20 m² in a 50 mm layer is 1 m³. A pack of 0,3 m³ means 4 packs, rounded up.
Questions
Two layers of 50 mm?
Either a thickness of 100 mm, or two separate areas.
Offcuts?
Add them into the area, or take one more pack. The formula trims by volume only.
Foam boards?
Yes, if you know how many cubic meters are in a pack.