Basement Insulation Calculator
Basement walls need continuous insulation on the concrete before anything gets framed. Enter your perimeter and ceiling height for sheet counts, R-value and cost.
Your project
Covers cuts, compression and odd bays. 10% is the usual default.
Your results
- Net wall area
- 1,012 sq ft
- 4×8 sheets required
- 32 sheets
- R-value achieved
- R-10
- Furring strips (2 ft OC)
- 64 pieces
- Material cost
- $850
- Installed cost (pro)
- $2,064
32 sq ft per sheet
Estimates use typical US material and labor pricing. Confirm quantities against the coverage chart on the bag before you buy.
Gear for this job
Rigid Foam Board Insulation
Multi Purpose XPS Foam Board,2 Pack 15.6x11.7X 2in Polystyrene Craft Foam Sheets,Rigid and Easy to Shape,DIY Modeling Art Projects, Party Decoration, Cosplay Prop Production, Carve,Heat Insulation
Check price on Amazon
Double-Layer Insulated Foam Panels, 3-Pack Insulation Seal Panels for Portable AC Window Vent Seal Kit, Thick Adjustable Insulation Board, Air Conditioner Window Gap Filler
Check price on Amazon
GCGOODS Window Air Conditioner Insulated Foam Panels, Winter Surround Insulation Side Panel with Top Seal Strip for Window AC Unit Indoor, White
Check price on Amazon
Foam Board Insulation Panels 2 Inch
Multi Purpose XPS Foam Board,2 Pack 15.6x11.7X 2in Polystyrene Craft Foam Sheets,Rigid and Easy to Shape,DIY Modeling Art Projects, Party Decoration, Cosplay Prop Production, Carve,Heat Insulation
Check price on Amazon
LuckyFoam Blue 4 Pack 15x12x2 inch Foam Sheets 2 Inch Thick | Polystyrene Rectangles XPS Foam Board Craft for Insulating DIY Modeling Art Supplies
Check price on Amazon
Fabbay 2 Pcs Pink XPS Foam Board 15" X 12" 2" Thick Rectangle Craft | Polystyrene Foam for Insulation, Modeling Art Supplies, Lightweight Pink Boards, Easy to Cut and Shape for DIY Projects
Check price on Amazon
House Wrap Insulation Tape
XFasten Foam Pipe Insulation Tape 2 Inch x 15 Feet Heavy-Duty AC Line Insulation Outdoor Pipe Wrap Tape AC Pipe Insulation Outdoor Pipe Insulation Wrap Tape HVAC Line Insulation Pipe Wrap Around Tape
Check price on Amazon
Vapor Barrier Tape 4" x180' 1 Roll Waterproof Seam Tape | White polyethylene tape for crawl spaces & moisture barriers, waterproof seam tape for underlayments, insulation & liners
Check price on Amazon
BlueTex Insulationㅤ 4'' Wide x 180' Long White Vapor Barrier Tape - 1 Roll, Waterproofing for Stucco, Crawlspaces, Repair, Underlayment Seams, Metal Building Seams, Excellent Air Barrier
Check price on Amazon
As an Amazon Associate we earn from qualifying purchases. Product links on this page may earn us a commission at no extra cost to you.
How this calculator works
- Net wall area = (perimeter × height − openings) × (1 + waste %)
- Sheets = net area ÷ 32 sq ft per 4×8 sheet
- R-value = R-per-inch × thickness
Frequently asked questions
Can I put fiberglass batts against a basement wall?
Not directly. Concrete wicks moisture and batts hold it against the wall, which grows mould. Put rigid foam or closed-cell spray foam on the concrete first, then frame and batt in front of it if you want more R.
What R-value do basement walls need?
Most codes want R-10 to R-15 continuous below grade. Two inches of XPS gets you R-10; polyiso hits R-12 at the same thickness.
Related calculators
Free app
Run this calculator on your phone
Offline-ready, saves your results, no signup.
Net wall area
1,012 sq ft