Cost guide · Insulation
How much R-13 insulation for 1,000 sq ft of wall?
24 packages of R-13 fiberglass batts, at 40 sq ft per package. Studs at 16 in on center take up about 9.4% of a wall, so 1,000 sq ft of wall has 906.25 sq ft of cavity. With 5% waste that is 24 packages, about $720.00 at $30.00 a package.
Prices Ballpark U.S. home-center figures, not quotes. Default price list reviewed . Enter local prices in the calculator for a tighter number.
Materials takeoff
How much R-13 insulation for 1,000 sq ft of wall? · https://estimahome.com/guides/r13-insulation-1000-sq-ft-wall/
Wall length (or attic length): 125 ftWall height (or attic width): 8 ftWindows and doors to subtract: 0 sq ftR-value: R-13 (2×4 wall)
- Net area
- 1000 sq ft
- Cavity share
- 90.6%
- Insulated area
- 906.3 sq ft
- Packages
- 24
| No. | Item | Qty | Unit | Unit cost | Amount |
|---|---|---|---|---|---|
| 1 | Fiberglass R-13, 15 in wide | 24 | pkg | $30.00 | $720.00 |
- Subtotal
- $720.00
- Likely range
- $612.00 – $828.00
- Use the R-value your local energy code requires for the wall, floor or attic you are insulating.
- Not included: vapor retarder, baffles, staples, gloves and a respirator.
Buy these materials
- 24 packages of R-13 insulationAmazon search for packages of R-13 insulation (opens in new tab)
Links open a store search for each item. Check sizes and grades against your plan.
Open the insulation calculator with these inputsChange any measurement, assumption or price and the takeoff updates.
How the numbers work
- Net wall: 125 ft × 8 ft − 0 sq ft of openings = 1,000 sq ft.
- Cavity share: (16 − 1.5) ÷ 16 = 90.63%.
- Insulated area: 1,000 × 0.9063 = 906.25 sq ft.
- Packages: 906.25 × 1.05 ÷ 40 sq ft = 23.79, rounded up to 24.
- Cost: 24 × $30.00 = $720.00.
Comparison
| Wall area | Cavity area | Packages | Materials |
|---|---|---|---|
| 250 sq ft | 227 sq ft | 6 | $180.00 |
| 500 sq ft | 453 sq ft | 12 | $360.00 |
| 1,000 sq ft | 906 sq ft | 24 | $720.00 |
| 1,500 sq ft | 1,359 sq ft | 36 | $1,080.00 |
| 2,000 sq ft | 1,813 sq ft | 48 | $1,440.00 |
Each row is a separate run of the Insulation Calculator at default prices. The highlighted row is the project above.
What changes the cost
- Package coverage
- Coverage per package varies by brand, R-value and width. 40 sq ft is a planning figure; the square footage printed on the bag changes the count directly.
- R-value and wall depth
- 2 × 4 walls take R-13 or R-15; 2 × 6 walls take R-19 or R-21. The $30.00 default is an R-13 package. Thicker batts cost more per square foot; change the price when you change the R-value.
- Faced or unfaced
- Kraft-faced batts include a vapor retarder and are common in exterior walls in cold climates, facing the heated side. Unfaced batts suit interior walls and sound control.
- Waste factor
- 5% covers cuts around boxes, pipes and short bays. Attics and walls with odd framing run higher.
- Openings and framing
- Subtract windows and doors. Corners, headers and blocking leave less cavity than the 16 in figure assumes, so the count runs a little high, which is the safe side.
- Labor versus DIY
- These are register prices for doing the work yourself. A contractor's bid adds labor, equipment, overhead, permit fees where they apply, and markup on materials, so it will run well above this figure. Get two or three written bids against the same plan and compare the material lists line by line. Wear gloves, long sleeves, eye protection and a dust mask or respirator. Cut batts to fit around wiring and boxes; do not compress them.
- Regional prices
- Default prices are ballpark U.S. home-center figures. Expect them to differ by region, season, brand and grade. Enter your store's prices in the calculator and every quantity on this page reprices. The R-value your energy code requires depends on your climate zone.
Questions
How many square feet in a package of R-13?
It varies by brand and width; 40 sq ft is used here. Check the bag and enter the figure in the calculator.
Do studs reduce how much insulation I need?
Yes. At 16 in on center with 1.5 in studs, about 90.6% of the wall is cavity. At 24 in on center it is about 93.8%.
Can I use R-13 in a 2x6 wall?
It fits but leaves the cavity partly empty. 2 × 6 walls are built for R-19 or R-21 batts, and your energy code may require them.
Figures computed with the Insulation Calculator and the default price list (/api/prices.json, reviewed October 20, 2026). Quantities are rounded up to what stores sell. Updated 2026-10-20.