Free planning tool
Insulation quantity estimator
Use measured surface areas and the coverage printed on your selected product. Calculate net coverage, an allowance for cuts and the number of whole packs for one layer.
How the result is worked out
Net area = gross area − openings. Purchase area = net area × (1 + allowance ÷ 100). Whole packs = round up(purchase area ÷ coverage per pack). Volume = purchase area × thickness.
What to keep in mind
This is a quantity takeoff. It does not choose insulation type, required R-value, vapour control or a safe roof assembly. Pack coverage must match the selected thickness. Include extra layers in separate runs.
Read the related guide: How to plan insulation quantities for an A-frame →