Free · Android
The Smart Insulation Calculator app
48 insulation calculators in your pocket — on the jobsite, in the attic, offline.
By Dixon App Studio · Free download
Works offline
No signal in a crawlspace? The math still runs.
Share results
Send a clean estimate to your contractor or supplier.
No signup
Open it and calculate. That's it.
Built for one hand
Big inputs and readable results on a ladder.
What's inside
- Every insulation calculator, no signup
- Works offline in attics and crawlspaces
- Save and share results with your contractor
- IECC climate-zone R-value targets built in
- Whole-house insulation cost from your square footage
Calculators in the app
The same tools you use here, offline on your phone.
- Insulation Area
- R-Value
- Attic Insulation
- Wall Insulation
- Blown-In Bags
- Batt Quantity
- Spray Foam Board Feet
- Insulation Cost
- Crawlspace Insulation
- Basement Insulation
- Garage Door Insulation
- Rim Joist Insulation
What the insulation app works out
Enter the area and the R-value you are aiming for, and the app gives the order: rolls or batts for walls and floors, bags and settled depth for blown-in cellulose or fiberglass, board count for rigid foam, and board feet for spray foam, each with a cost estimate at 2026 prices. If you do not know the target, pick your climate zone and it uses the DOE recommendation for attics, walls and floors.
It is the same set of estimates as the calculators on this site, built to run without a signal, which is the point in an attic or crawlspace. For a quick check before you buy, the how much insulation do I need page walks through the same maths by hand.
Download
Free on Google Play for Android phones and tablets. On an iPhone or iPad, every calculator works in Safari right here on the site.
Why an app when the site already works on a phone?
Because attics have no signal. The moment you actually need to know how many bags to buy is usually while standing on a joist with a tape measure, in a space with a metal roof over it and no bars showing. Everything in the app runs on the device, so a dead connection changes nothing.
It is the same arithmetic as the website, built from the same shared data file of R-values, coverage ratings and 2026 prices — not a reduced version. If a figure is corrected here it is corrected there.
Nothing you type is uploaded. The calculators run locally, so your measurements and your budget stay on your phone.
What it is good at
Standing in the aisle comparing two bags. Bag coverage is printed as total R-value times square feet, which is not a number anyone converts in their head — enter the rating and the area and it tells you how many bags, for either bag.
Checking a quote in the driveway before the contractor leaves. Enter the area, the material and the target R-value and you have the national average for that job to hold the number against.
Working out how deep to blow. The depth that gets you to R-49 depends entirely on the material — roughly 20 inches of blown fiberglass, about 14 of cellulose — and that is exactly the sort of thing worth having to hand rather than remembering.
Availability and cost
Free, with no account and no email gate, the same as the website. There is no paid tier holding back a calculator.
The app is Android-only. On an iPhone or iPad, use this site in Safari — every calculator runs in the browser, and you can add it to your home screen.
If you would rather not install anything, every calculator on this site works in a mobile browser and always will. The app exists for the offline case, not to move anyone off the web.