Attic Insulation Cost & Payback Calculator

How to use this calculator

Enter your attic floor area, pick your climate zone, and say roughly how much insulation is there now. The calculator shows ENERGY STAR's recommended amount to add, the installed cost for the type you choose, and how long the energy savings take to pay it back. To check your current level, measure the depth of the insulation between the attic floor joists.

How this is calculated

Cost is your attic area times a national installed price per square foot for the insulation type, plus removal of the old insulation if you select it. Savings is your annual heating and cooling bill times ENERGY STAR's modeled savings for your climate zone, which ranges from 7% in the warmest zone to 20% in the coastal Pacific Northwest. Payback is cost divided by annual savings.

Example

A 1,000 square foot attic in climate zone 4 with about 3–4 inches of insulation needs about R-49 added. Blown-in insulation costs $900–$2,400; with a $900 heating and cooling bill, the 17% savings is about $153 a year, for a payback of roughly 6–16 years.

What the savings assume

ENERGY STAR's estimate covers sealing air leaks as well as adding insulation, so ask your installer to air-seal the attic floor before insulating. The per-square-foot prices don't rise with the amount you add, so a job adding R-60 will tend toward the top of the range.

Estimate only, based on published 2026 national price ranges and ENERGY STAR's recommended R-values and modeled savings. The federal Section 25C credit for insulation expired for work placed in service after December 31, 2025, and isn't included here. Many utilities still offer insulation rebates — check locally.