Insulation quantity calculator
Enter the length and width of the surface you want to insulate. The calculator returns its area, in square feet or in square meters.
To get a number of packs, type the coverage printed on the pack you plan to buy. Add a waste allowance if you want to order extra for cuts; leave it empty for none.
Area to insulate 240 sq ft Area to order 240 sq ft
Method and limitations
Area to insulate = length × width. Area to order = area × (1 + waste ÷ 100), where the waste allowance is the percentage you type, and 0% when the field is empty. Packs = area to order ÷ coverage of one pack, rounded up to a whole pack; the coverage is the one you read on the label, in square feet (imperial) or square meters (metric), and no pack size is assumed. The result is the area of a plain rectangle: openings, framing, overlaps, thickness and the thermal performance needed are not computed. This is a geometric calculation, so no external source is needed.
Sources
No external reference is documented for this calculation; its method and limitations are described above.
