Whole-House Insulation Cost Calculator

Enter the size of the house and what you want insulated. The calculator works out the attic, exterior wall and crawlspace or basement areas from the square footage, prices each at this site's 2026 installed rates, and applies your state's labor index — so you see where the money goes before you call for quotes.

Your project

Each state's labor index from this site's state cost pages.

Gear for this job

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Prices as of Oct 3, 2026, 4:39 AM UTC. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.

How this calculator works

  • Footprint = floor area ÷ stories; attic = footprint
  • Perimeter = 2 × (1.5w + w), where 1.5w × w = footprint
  • Wall area = perimeter × ceiling height × stories × 0.85 (15% windows and doors)
  • Each surface = area × 2026 installed rate × state labor index

Cost to insulate common houses (national average labor)

House and scopeTotalPer sq ft
1,200 sq ft ranch, attic only$2,220$1.85
1,500 sq ft ranch, attic + walls retrofit$5,570$3.71
2,000 sq ft two-story, attic + walls + crawlspace$8,515$4.26
2,500 sq ft two-story, everything + basement$13,571$5.43
2,000 sq ft new build, open walls + attic$4,923$2.46

Computed with the calculator above. Rates: attic blown fiberglass $1.85, attic batts $1.60, removal $1.55, wall batts $1.75, dense-pack $2.60, crawlspace $2.10, basement rigid foam $3.10 per sq ft installed.

This site's typical whole-house job ranges (national baseline)

JobTypical range
Attic top-up (1,500 sq ft)$1,500 – $2,600
Full attic removal + re-insulate$3,200 – $5,400
Whole-house wall retrofit (2,000 sq ft home)$4,200 – $7,800
Crawlspace encapsulation + insulation$3,800 – $9,000
Garage conversion insulation$900 – $2,200
Whole-home spray foam (new build)$7,500 – $16,000

Worked example: a 2,000 sq ft two-story house on a crawlspace

Two stories make a 1,000 sq ft footprint — the attic floor. A 1.5 : 1 rectangle of that size is about 25.8 × 38.7 ft, a perimeter of 129 ft. At 8 ft ceilings over two stories that is 2,066 sq ft of exterior wall, less 15% for windows and doors: 1,756 sq ft.

Blowing the attic to R-49 at $1.85 is $1,850; dense-packing the walls at $2.60 is $4,565; the crawlspace at $2.10 is $2,100. Total $8,515, or $4.26 per square foot of house. The walls are the biggest line because there is more wall than attic in a two-story house.

Where to start if the budget won't stretch

Air-seal and insulate the attic first: it is the cheapest surface per square foot and usually the worst insulated. Then the crawlspace or rim joists, then the walls. Walls cost more because the insulation goes in through holes drilled from outside or inside and every bay has to be filled.

Get the attic and walls quoted separately, and ask each contractor what R-value and material they are quoting, whether air sealing is included and whether old insulation is being removed.

Keep going

Frequently asked questions

How much does it cost to insulate a house?

On this calculator a 2,000 sq ft two-story house costs about $8,515 to insulate — attic blown to R-49, walls dense-packed and the crawlspace insulated — at national-average labor. The attic alone on a 1,200 sq ft ranch is about $2,220.

How much does it cost to insulate a 1,500 sq ft house?

About $5,570 for a single-story 1,500 sq ft house with the attic blown to R-49 and the existing walls dense-packed, or $2,775 for the attic only.

What is the cost per square foot to insulate a house?

Roughly $1.85 per square foot of house for an attic-only job and $4.26–$5.43 for attic, walls and foundation. Per square foot of surface, installed rates run from $1.55 for removal to $3.60 for closed-cell spray foam.

Is it worth insulating the walls of an old house?

Often, if they are empty: dense-pack cellulose through drilled holes fills each bay without opening the walls. But it costs more per square foot than the attic and the payback is slower, so do the attic and air sealing first.

Why does my state change the price?

Labor is most of an insulation bill, so the calculator multiplies each rate by the state labor index used on this site's state cost pages — from about 0.85 in the lowest-cost states to over 1.4 in Alaska.

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Estimated total, installed

$8,515

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