About SmartInsulationCalculator

Insulation is one of the highest-return upgrades a house can get, and one of the easiest to get wrong. Bags are sold by coverage rating, batts by bag square footage, spray foam by the board foot, and every product uses a different unit. Most people give up and guess.

Every calculator here takes plain measurements — length, width, depth, climate zone — and returns the numbers you actually order from: bags, batts, board feet, inches and dollars.

R-value per inch figures follow published manufacturer ranges and Department of Energy guidance. Recommended R-value targets follow the DOE climate-zone map for attics, walls and floors.

Cost figures are national averages assembled from big-box retail pricing and contractor quote ranges, then refreshed for 2026. They are estimates, not quotes — regional labor swings can move an installed price by 30% in either direction.

The site is funded by affiliate commissions. When you buy insulation tools or materials through our Amazon links (associate tag SmartInsulationCalculator-20) we earn a small commission at no extra cost to you.

No calculator result is influenced by what a manufacturer pays. Nobody pays for placement here.