Regional cost data · 51 markets

Insulation cost by state

What attic insulation costs per square foot installed, across all 50 states and DC. The US baseline is $2.00, but the spread from the cheapest market to the priciest is about 61% — so where you live changes the budget more than almost any other single factor.

Reviewed by The CostToUpgrade Estimating Desk Last reviewed June 2026 How we estimate

US national average

$2.00

per square foot installed

Most expensive: $2.70HI
Least expensive: $1.68MS
Top-to-bottom spread: 61%

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Planning estimates, not quotes. Confirm locally.

Cost by region

Regional averages smooth out single-state noise and show the broad pattern.

Northeast

$2.23

+12% vs national · 9 states

Midwest

$1.89

-5% vs national · 12 states

South

$1.86

-7% vs national · 17 states

West

$2.14

+7% vs national · 13 states

What that means for a real project

National-average pricing applied to common project sizes:

Project size	US average range
Compact 120 ft²	$211 – $269
Typical 300 ft²	$528 – $672
Large 600 ft²	$1,056 – $1,344

Every state, ranked

All 50 states plus DC. The typical-project column applies each state's unit price to a 300 ft² job.

Insulation cost per square foot installed by US state
State	Region	Unit price	vs US avg	300 ft² project
Alabama	South	$1.72	-14%	$453–$579
Alaska	West	$2.56	+28%	$675–$861
Arizona	West	$1.94	-3%	$513–$651
Arkansas	South	$1.70	-15%	$450–$570
California	West	$2.60	+30%	$687–$873
Colorado	West	$2.08	+4%	$549–$699
Connecticut	Northeast	$2.32	+16%	$612–$780
Delaware	South	$2.04	+2%	$540–$684
District of Columbia	South	$2.44	+22%	$645–$819
Florida	South	$1.92	-4%	$507–$645
Georgia	South	$1.80	-10%	$474–$606
Hawaii	West	$2.70	+35%	$714–$906
Idaho	West	$1.90	-5%	$501–$639
Illinois	Midwest	$2.16	+8%	$570–$726
Indiana	Midwest	$1.86	-7%	$492–$624
Iowa	Midwest	$1.84	-8%	$486–$618
Kansas	Midwest	$1.78	-11%	$471–$597
Kentucky	South	$1.76	-12%	$465–$591
Louisiana	South	$1.76	-12%	$465–$591
Maine	Northeast	$2.06	+3%	$543–$693
Maryland	South	$2.14	+7%	$564–$720
Massachusetts	Northeast	$2.42	+21%	$639–$813
Michigan	Midwest	$1.90	-5%	$501–$639
Minnesota	Midwest	$2.04	+2%	$540–$684
Mississippi	South	$1.68	-16%	$444–$564
Missouri	Midwest	$1.80	-10%	$474–$606
Montana	West	$1.92	-4%	$507–$645
Nebraska	Midwest	$1.80	-10%	$474–$606
Nevada	West	$2.06	+3%	$543–$693
New Hampshire	Northeast	$2.12	+6%	$561–$711
New Jersey	Northeast	$2.30	+15%	$606–$774
New Mexico	West	$1.82	-9%	$480–$612
New York	Northeast	$2.48	+24%	$654–$834
North Carolina	South	$1.78	-11%	$471–$597
North Dakota	Midwest	$1.88	-6%	$495–$633
Ohio	Midwest	$1.88	-6%	$495–$633
Oklahoma	South	$1.72	-14%	$453–$579
Oregon	West	$2.16	+8%	$570–$726
Pennsylvania	Northeast	$2.04	+2%	$540–$684
Rhode Island	Northeast	$2.26	+13%	$597–$759
South Carolina	South	$1.76	-12%	$465–$591
South Dakota	Midwest	$1.80	-10%	$474–$606
Tennessee	South	$1.78	-11%	$471–$597
Texas	South	$1.86	-7%	$492–$624
Utah	West	$1.96	-2%	$516–$660
Vermont	Northeast	$2.10	+5%	$555–$705
Virginia	South	$1.96	-2%	$516–$660
Washington	West	$2.24	+12%	$591–$753
West Virginia	South	$1.80	-10%	$474–$606
Wisconsin	Midwest	$1.94	-3%	$513–$651
Wyoming	West	$1.86	-7%	$492–$624

Unit prices are the national baseline scaled by each state's relative construction cost index. Project totals apply a ±12% band to reflect normal quote variation.

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How we build these numbers

We start from a US national baseline of $2.00 per square foot installed and multiply it by each state's relative construction cost index, where 1.00 is the national average. Those indices are directional — they capture broad differences in trade wages, material freight, and permitting overhead, not street-level pricing.

The ±12% band on every figure is deliberate. It reflects the range we would expect between a competitive bid and a premium one for the same scope in the same market. If a quote lands far outside that band in either direction, the scope is probably different from what you think it is — that is worth a conversation before it is worth a signature.

Full detail on sources, review cadence, and what these estimates deliberately exclude is on our methodology page.

Insulation cost by state: FAQ

How much does attic insulation cost on average in the US?

The national baseline we use is $2.00 per square foot installed. Applied to a typical typical project of 300 ft², that works out to roughly $528–$672 in materials at the unit shown. Labor, delivery, tax, and site prep sit on top unless the unit label says "installed."

Which states are most and least expensive for attic insulation?

The five priciest markets in our index are Hawaii, California, Alaska, New York, District of Columbia — Hawaii runs about $2.70 per square foot installed. The five cheapest are Mississippi, Arkansas, Oklahoma, Alabama, South Carolina, with Mississippi near $1.68. Top to bottom that is a spread of roughly 61%, which is why a national average alone is a poor budgeting tool.

Why does the same project cost so much more in some states?

Four things move the number: prevailing wage rates for the trades, freight distance from the nearest supplier or plant, permitting and inspection overhead, and local demand. Labor is usually the biggest lever — in high-wage metros it can be well over half the installed price. Freight matters most for heavy, low-value materials like concrete, gravel, and block, where hauling costs rival the material itself.

Are these numbers quotes?

No. They are directional planning figures built from a national baseline and a relative state cost index, and they are deliberately shown as ranges. Use them to sanity-check a bid or set a budget, not to negotiate a contract. Two contractors in the same ZIP code can legitimately differ by 20–30% based on crew size, backlog, and scope assumptions.

How do I get a number for my specific project?

Run the Insulation Calculator with your own dimensions and your local unit price. The calculator does the quantity math exactly; this page just tells you what unit price is realistic where you live. Together they give you a defensible budget before you call anyone.