Calculate the amount of batt or roll insulation needed for your walls, attic, or crawlspace. Enter the area dimensions and stud spacing to get the number of batts or rolls and total square footage of insulation required.
Enter Your Measurements
Results
Area to Insulate
313
sq ft
Batts Needed
38
batts
Rolls (40 sq ft each)
8
rolls
Stud Cavities
38
cavities
Gross Wall Area
400
sq ft
Formula
How to Use This Calculator
How to Use
- 1
Enter the total wall length (perimeter for a full room, or just the walls being insulated).
- 2
Enter the wall height in feet.
- 3
Select the stud spacing (16 inches on center is standard).
- 4
Enter the number of doors and windows to subtract from the area.
Frequently Asked Questions
Frequently Asked Questions
What R-value insulation do I need for walls?
Can I put new insulation over old insulation?
In-Depth Guides
Insulation R-Value Guide: What You Need by Climate Zone
Understand insulation R-values for your climate zone. Covers DOE recommendations for attics, walls, and floors, plus R-value per inch for all common insulation types.
Insulation Costs in Alabama: 2026 Price Guide
How much does insulation cost in Alabama? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Alabama's climate zone.
Insulation Costs in Alaska: 2026 Price Guide
How much does insulation cost in Alaska? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Alaska's climate zone.
Insulation Costs in Arizona: 2026 Price Guide
How much does insulation cost in Arizona? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Arizona's climate zone.
Insulation Costs in Arkansas: 2026 Price Guide
How much does insulation cost in Arkansas? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Arkansas's climate zone.
Insulation Costs in California: 2026 Price Guide
How much does insulation cost in California? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for California's climate zone.
Insulation Costs in Colorado: 2026 Price Guide
How much does insulation cost in Colorado? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Colorado's climate zone.
Insulation Costs in Connecticut: 2026 Price Guide
How much does insulation cost in Connecticut? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Connecticut's climate zone.
Insulation Costs in Delaware: 2026 Price Guide
How much does insulation cost in Delaware? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Delaware's climate zone.
Insulation Costs in Florida: 2026 Price Guide
How much does insulation cost in Florida? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Florida's climate zone.
Insulation Costs in Georgia: 2026 Price Guide
How much does insulation cost in Georgia? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Georgia's climate zone.
Insulation Costs in Hawaii: 2026 Price Guide
How much does insulation cost in Hawaii? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Hawaii's climate zone.
Insulation Costs in Idaho: 2026 Price Guide
How much does insulation cost in Idaho? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Idaho's climate zone.
Insulation Costs in Illinois: 2026 Price Guide
How much does insulation cost in Illinois? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Illinois's climate zone.
Insulation Costs in Indiana: 2026 Price Guide
How much does insulation cost in Indiana? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Indiana's climate zone.
Insulation Costs in Iowa: 2026 Price Guide
How much does insulation cost in Iowa? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Iowa's climate zone.
Insulation Costs in Kansas: 2026 Price Guide
How much does insulation cost in Kansas? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Kansas's climate zone.
Insulation Costs in Kentucky: 2026 Price Guide
How much does insulation cost in Kentucky? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Kentucky's climate zone.
Insulation Costs in Louisiana: 2026 Price Guide
How much does insulation cost in Louisiana? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Louisiana's climate zone.
Insulation Costs in Maine: 2026 Price Guide
How much does insulation cost in Maine? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Maine's climate zone.
Insulation Costs in Maryland: 2026 Price Guide
How much does insulation cost in Maryland? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Maryland's climate zone.
Insulation Costs in Massachusetts: 2026 Price Guide
How much does insulation cost in Massachusetts? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Massachusetts's climate zone.
Insulation Costs in Michigan: 2026 Price Guide
How much does insulation cost in Michigan? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Michigan's climate zone.
Insulation Costs in Minnesota: 2026 Price Guide
How much does insulation cost in Minnesota? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Minnesota's climate zone.
Insulation Costs in Mississippi: 2026 Price Guide
How much does insulation cost in Mississippi? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Mississippi's climate zone.
Insulation Costs in Missouri: 2026 Price Guide
How much does insulation cost in Missouri? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Missouri's climate zone.
Insulation Costs in Montana: 2026 Price Guide
How much does insulation cost in Montana? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Montana's climate zone.
Insulation Costs in Nebraska: 2026 Price Guide
How much does insulation cost in Nebraska? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Nebraska's climate zone.
Insulation Costs in Nevada: 2026 Price Guide
How much does insulation cost in Nevada? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Nevada's climate zone.
Insulation Costs in New Hampshire: 2026 Price Guide
How much does insulation cost in New Hampshire? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for New Hampshire's climate zone.
Insulation Costs in New Jersey: 2026 Price Guide
How much does insulation cost in New Jersey? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for New Jersey's climate zone.
Insulation Costs in New Mexico: 2026 Price Guide
How much does insulation cost in New Mexico? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for New Mexico's climate zone.
Insulation Costs in New York: 2026 Price Guide
How much does insulation cost in New York? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for New York's climate zone.
Insulation Costs in North Carolina: 2026 Price Guide
How much does insulation cost in North Carolina? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for North Carolina's climate zone.
Insulation Costs in North Dakota: 2026 Price Guide
How much does insulation cost in North Dakota? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for North Dakota's climate zone.
Insulation Costs in Ohio: 2026 Price Guide
How much does insulation cost in Ohio? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Ohio's climate zone.
Insulation Costs in Oklahoma: 2026 Price Guide
How much does insulation cost in Oklahoma? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Oklahoma's climate zone.
Insulation Costs in Oregon: 2026 Price Guide
How much does insulation cost in Oregon? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Oregon's climate zone.
Insulation Costs in Pennsylvania: 2026 Price Guide
How much does insulation cost in Pennsylvania? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Pennsylvania's climate zone.
Insulation Costs in Rhode Island: 2026 Price Guide
How much does insulation cost in Rhode Island? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Rhode Island's climate zone.
Insulation Costs in South Carolina: 2026 Price Guide
How much does insulation cost in South Carolina? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for South Carolina's climate zone.
Insulation Costs in South Dakota: 2026 Price Guide
How much does insulation cost in South Dakota? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for South Dakota's climate zone.
Insulation Costs in Tennessee: 2026 Price Guide
How much does insulation cost in Tennessee? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Tennessee's climate zone.
Insulation Costs in Texas: 2026 Price Guide
How much does insulation cost in Texas? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Texas's climate zone.
Insulation Costs in Utah: 2026 Price Guide
How much does insulation cost in Utah? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Utah's climate zone.
Insulation Costs in Vermont: 2026 Price Guide
How much does insulation cost in Vermont? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Vermont's climate zone.
Insulation Costs in Virginia: 2026 Price Guide
How much does insulation cost in Virginia? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Virginia's climate zone.
Insulation Costs in Washington: 2026 Price Guide
How much does insulation cost in Washington? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Washington's climate zone.
Insulation Costs in West Virginia: 2026 Price Guide
How much does insulation cost in West Virginia? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for West Virginia's climate zone.
Insulation Costs in Wisconsin: 2026 Price Guide
How much does insulation cost in Wisconsin? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Wisconsin's climate zone.
Insulation Costs in Wyoming: 2026 Price Guide
How much does insulation cost in Wyoming? 2026 price ranges for batt, blown-in, and spray foam insulation — with R-value recommendations for Wyoming's climate zone.
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About This Calculator
This calculator uses the formula: Net Area = (Wall Length × Height) - (Doors × 21) - (Windows × 15) | Batts = Wall Length × 12 ÷ Stud Spacing. All calculations follow industry-standard methods. Results are estimates — always verify with a licensed professional for structural or code-compliant work.
Built and maintained by the CalcSmart team. Last updated March 2026.
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