Estimate batt/roll insulation packs or blown-in insulation bags from area, coverage and waste — metric or imperial.
Informational only - shown in your results, does not affect the calculation.
Computed area: —
Enter your specific product's coverage per pack/roll from its label - this varies by brand, thickness and R-value.
Covers offcuts and fitting losses around cavities, obstructions and irregular framing - not a substitute for measuring your actual layout.
| Item | Value |
|---|
Choose Batt / Roll for wall, ceiling or floor batts, Blown-In / Loose-Fill for attic cellulose or blown fiberglass, or Spray Foam for a spray-applied kit.
Enter your area (or use the Advanced section to calculate it from dimensions or a wall with door/window openings), and your specific product's coverage, depth/yield or board-foot kit yield - these vary significantly by brand, thickness and R-value, so this calculator doesn't assume a fixed figure for you.
Add a purchase allowance and use the Cost tab with your local prices, priced separately per material.
For batt or roll insulation, divide the area you're covering by the coverage area of one pack, add a purchase allowance, and round up to a whole number of packs.
For blown-in or loose-fill insulation, this calculator offers two methods.
The coverage method divides area by the bag's stated coverage area at your target depth (printed on the bag - it is not simply area multiplied by depth, since a bag covers less area at a deeper fill).
The volume-yield method instead multiplies area by depth to get a volume, then divides by the bag's stated yield volume.
For spray foam, the industry-standard unit is board feet - area in square feet multiplied by thickness in inches - divided by the kit's board-foot yield.
Batt (or roll) insulation is precut or rolled to standard widths matching common stud and joist spacing, and is installed by hand - coverage is simply the pack's stated area.
Blown-in or loose-fill insulation (commonly cellulose or blown fiberglass) is machine-blown into attics or wall cavities and estimated by coverage area at a given depth, or by a stated volume yield.
Spray foam is sprayed on-site as a liquid that expands and cures, and is estimated in board feet with a kit yield that varies significantly by foam type, ambient conditions and application technique - always use your kit manufacturer's own documented yield rather than a generic figure.
Unlike volume-based materials like concrete or gravel, insulation coverage, yield or board-foot rating per pack, bag or kit is set by the manufacturer and depends on the R-value, thickness and material blend - there's no single "typical" figure that applies across brands.
This calculator asks for your product's specific coverage or yield rather than assuming a number, so your result matches the product you're actually buying.
If you haven't chosen a product yet, check a few manufacturer datasheets at your target R-value to compare material quantity before you decide.
The Cost tab prices batt/roll, blown-in and spray foam separately from the pack/bag/kit counts calculated on each tab - it does not automatically add them together, since these are normally alternative approaches rather than materials bought for the same job.
A "Compare All" view is available to see the three side by side, clearly labelled as a comparison rather than a combined total.
An optional equipment/hire cost (for example a blower for blown-in, or a spray rig for spray foam) can be entered separately from material cost. Vapour barrier and installation labour aren't included.
Batt/roll. A 100 m² ceiling area with a batt pack covering 8.36 m² and a 10% purchase allowance: area with allowance = 100 × 1.10 = 110 m², needing CEILING(110 ÷ 8.36) = 14 packs.
Blown-in (coverage method). A 120 m² attic filled to 270mm depth, with a bag covering 2.8 m² at that depth and a 10% allowance: area with allowance = 132 m², needing CEILING(132 ÷ 2.8) = 48 bags.
Blown-in (volume-yield method). A 100 m² attic filled to 300mm depth needs a volume of 100 × 0.3 = 30 m³, before dividing by the bag's stated yield volume and applying any allowance.
Spray foam. A 1,000 ft² area at 2in thickness needs 1,000 × 2 = 2,000 board feet.
With a 600 board-foot kit yield: at 0% allowance, CEILING(2,000 ÷ 600) = 4 kits; at 10% allowance, adjusted board feet = 2,200, still CEILING(2,200 ÷ 600) = 4 kits (the allowance doesn't always push the count to the next kit).
The most common mistake is using a generic "typical" coverage or yield figure instead of the one printed on the specific product being purchased - coverage can vary by more than double between products at different R-values, so a generic number can leave a project significantly short or over-ordered.
For blown-in insulation, another frequent error is treating the coverage-per-bag-at-depth figure as if it were simply area × depth, or using the bag's coverage at a different depth than actually planned, since coverage area drops as fill depth increases.
It's also easy to forget that loose-fill settles somewhat after installation - there is no single universal settling factor, so following the manufacturer's fresh-installed coverage (not an already-settled figure) avoids under-filling.
For spray foam, using a generic kit yield instead of the manufacturer's documented figure for your specific ambient conditions is a common source of error, since yield is sensitive to temperature and humidity.
This calculator estimates material quantity from the area, depth/thickness and product coverage or yield you enter.
It does not determine the R-value required for your climate zone, wall/ceiling/roof assembly performance, vapour barrier requirements, ventilation or fire/ignition-barrier requirements for spray foam, or building/energy code compliance.
There is no single universal settling factor for loose-fill insulation, and spray foam kit yield is not standardised - both must come from your specific product's documentation.
This tool is for general planning only - confirm your requirements against your local energy code or a qualified professional before purchasing.
Divide the area to be insulated by your specific product's coverage per pack (for batts/rolls), use a coverage-per-bag-at-depth or volume-yield-per-bag method (for blown-in), or divide board feet by kit yield (for spray foam), then round up.
Coverage and yield vary by brand, R-value and thickness, so use the figure from your product's label rather than a generic estimate. Use the tabs above for an automatic count.
The coverage-per-bag method divides your area by the bag's stated coverage area at your target depth (printed on the bag, since a bag covers less area at a deeper fill) - it is not simply area multiplied by depth.
If your product instead states a volume yield per bag, use the volume-yield method: multiply area by depth to get the volume needed, then divide by the bag's yield volume.
Use the Blown-In / Loose-Fill tab above for an automatic calculation with either method.
This depends entirely on your target depth/R-value and your specific bag's coverage or yield rating, which is printed on the bag and varies by brand.
Enter your area and your bag's stated coverage (or yield) on the Blown-In / Loose-Fill tab above for an exact count for your product.
Divide the area you're insulating by the coverage area of one roll or batt pack (printed on the product), add a purchase allowance, and round up.
Use the Batt / Roll tab above with your product's coverage for an automatic count.
Batt (or roll) insulation comes in precut or rolled sections sized to fit standard stud/joist spacing and is installed by hand.
blown-in (loose-fill) insulation - commonly cellulose or fiberglass - is machine-blown into attics or wall cavities and is estimated by coverage area or by volume.
spray foam is sprayed on-site as a liquid that expands and cures, and is estimated in board feet (area × thickness in inches) with kit yield that varies by foam type and application.
Spray foam is estimated in board feet - area in square feet multiplied by thickness in inches - then divided by the kit's stated board-foot yield and rounded up to a whole number of kits.
Kit yield varies significantly by foam type, ambient temperature, humidity and application technique, so always confirm against your specific kit manufacturer's documented yield rather than a generic figure. Use the Spray Foam tab above for an automatic calculation.
Yes - a higher R-value at a given depth, or a deeper/thicker application for the same material, generally means less area is covered per bag, pack or kit, since more material is being spread per square foot.
Always use the coverage or yield figure that matches your specific target depth/thickness and R-value, printed on the product label.
Material cost depends on insulation type (batt, blown-in, spray foam), R-value and local prices.
Batt, blown-in and spray foam are priced separately on the Cost tab - they are normally alternative approaches, not materials purchased together; an optional equipment/hire cost (e.g. a blower or spray rig) can be added separately from material cost, and installation labour is not included.
No - it estimates material quantity from the area, depth/thickness and product coverage or yield you enter, not the R-value required for your climate zone or building code.
Confirm your required R-value against your local energy code before choosing a product and depth.