How to use
- Enter the net area actually receiving insulation. Deduct openings and account for framing or cavities in your measurement plan.
- Use useful pack coverage from the label, or supply actual board, batt or roll dimensions and units per pack.
- Set identical layers and a chosen allowance. Add a pack price and optional layer thickness if known.
- Check layer area, required units, full packs and purchase excess. Changing the product-input method clears product data that need confirmation.
Calculation method
Material area = net area × identical layers. Target area adds the allowance. Label coverage mode rounds target area / pack coverage up to complete packs. Dimension modes first derive useful unit area, round required units up, then round units to full packs. Purchased area follows the bought pack count. Optional thickness provides a geometric volume only; price applies to complete packs, not the rounded display area.
Worked example
For 50 m², two identical layers, 10% allowance and 6 m² pack coverage, the target is 110 m². Nineteen packs supply 114 m². At 30 USD per pack the cost is 570 USD. With 1200 × 600 mm boards and eight per pack, one board covers 0.72 m². One layer at the same allowance needs 77 whole boards and ten packs, supplying 80 boards or 57.6 m².
Assumptions and limits
This is an area-based purchase estimate, not a thermal or fitting design. It does not calculate R/U-values, climate requirements, appropriate thickness, support spacing, fixings or cutting optimization. Different products or layer thicknesses need separate estimates. Nominal purchase volume is not necessarily compressed package volume, and coverage must match the selected thickness.
Continue your plan
Measure faces with the area calculator, plan a separate lining with the drywall calculator, or estimate covering packs with the roofing material calculator.
Copy, download or print a valid result to keep the inputs with the estimate. Currency selections label your prices; they do not apply an exchange rate. Product-dependent examples should be replaced with data for the material or equipment you actually use.
For the measurement and planning details, read planning insulation layers and whole-pack coverage.