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Insulation Cost Calculator (2026)

Estimate the cost to insulate. Pick area, insulation type (batt, blown, spray foam, rigid foam, radiant), R-value, and air-sealing. 2026 data; not a contractor bid.

By Martin Lashgari, Ph.D., P.E., PMP · Last reviewed July 2026

Attic mid-insulation with pink fiberglass batts installed between rafters, a vapor-barrier floor, and a two-tank spray-foam rig staged in the foreground

Enter your insulation project

Includes labor, equipment, and contractor markup.

Common projects

Area & material

Attic floor area, wall cavity sf, or rim/crawl perimeter area.
Uses the first 3 digits as a planning zone (not exact local pricing). Overrides state average when matched.

Air sealing & prep

Your insulation estimate

Estimated installed range
Calculating…
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Materials
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Labor
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Per sq ft
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Cost breakdown

ItemQuantityEstimated range
Planning estimate, not a bid. 2026 ranges informed by Energy Star, DOE Energy Saver, IECC 2024, manufacturer (Owens Corning, Rockwool, Knauf, Icynene) MSRP, HomeGuide, Homewyse.
What's not included: Federal 25C tax credit (applied to property placed in service on or before December 31, 2025; 2026 installs generally do not qualify — verify on IRS Form 5695), state utility rebates (Mass Save, NYSERDA), asbestos vermiculite abatement (older homes with Zonolite), bath-fan and recessed-light air sealing covers, rim-joist treatment, and HERS verification.

Bid check

Got an insulation contractor quote? Compare it to the planning range.

Quote per sq ft
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Range check
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Scope risk
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Add a quote amount to compare it against the current estimate.

Methodology & sources

What this is: a planning-range insulation calculator informed by 2026 cost guides, DOE recommendations, and manufacturer pricing (Owens Corning, Knauf, Rockwool, Johns Manville, Icynene).

Material pricing is per-sq-ft for the relevant assembly (cavity, attic floor, foundation wall). 5% waste added to ordered quantity.

Labor is modeled from per-unit installed rates with a crew-rate sanity check ($50-$90/crew-hr loaded billing rate), informed by BLS OEWS 47-2131 (Insulation Workers, Floor/Ceiling/Wall).

R-value targets follow ENERGY STAR seal-and-insulate guidance by IECC climate zone and the 2024 IECC code minimums.

Last updated: July 2026. Full methodology →

Helpful materials & tools for this project

Insulation is the material plus the barriers and safety gear to install it:

  • Batt or blown insulation — Fiberglass or cellulose, rated by R-value.
  • Vapor barrier — Controls moisture in walls and crawl spaces.
  • Blower rental — For blown-in attic insulation.
  • Respirator & gloves — Required PPE for handling insulation.

Suggested materials to help you plan — not an endorsement, and never a contractor referral.

Cost simulator Monte Carlo simulation See the full range of likely costs — with the odds

For a typical 800 sf walls fiberglass batt, the installed planning band runs $2,856 to $4,820 nationally before regional adjustment.

What this project costs in different metros

Regional labor and material markets move the installed price. These bands come from the same engine as the calculator above, run at each metro's real cost multipliers — enter your ZIP in the calculator for a figure tuned to your exact area. National reference: $2,850–$4,800.

MetroTypical installed rangevs. national
San Francisco, CA$3,750–$6,350+31%
New York, NY$3,800–$6,500+34%
Boston, MA$3,250–$5,550+15%
Chicago, IL$3,500–$6,000+24%
Atlanta, GA$3,400–$5,800+20%
Houston, TX$3,150–$5,350+11%
Miami, FL$2,850–$4,8000%
Phoenix, AZ$3,000–$5,100+5%

Planning ranges, not contractor quotes. Multipliers are rounded regional planning indices (see methodology), not a reproduction of any proprietary cost table.

What moves this price the most

Vary one input across its full range while holding everything else at the typical scenario, and this is how far each choice can move the installed estimate — measured by running the calculator's own engine. The widest bars are where your decisions matter most; the figures show the cheapest-to-priciest span each input creates on its own.

  • Area (sq ft)$1,350–$38,100
  • Insulation type$2,800–$6,200
  • Air sealing (penetrations)$3,000–$3,850
  • Remove old insulation$3,850–$4,650
  • Vapor barrier$3,850–$4,250
  • Permit$3,850–$3,950

A tornado view: each row varies a single input; a real project moves several at once, so totals aren't additive.

Related calculators — Interior finishes

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Insulating as part of an energy upgrade? ElectrifyCost's insulation calculator ties R-value targets to heating and cooling savings by climate zone.

See all calculators →

Guides for this project

What drives project costsSize beats material choice in 77% of projects Why small jobs cost more per sq ftSame spec, quarter the size: 1.84x per unit Why contractor quotes differMarkup explains ~10%; scope explains the rest What a contractor quote should include10-point checklist to read a bid before you sign 2026 Home Improvement Cost IndexMedian project costs across all 52 trades

All cost guides →

How much does insulation cost in 2026?

Insulation runs $1 to $5 per square foot installed in 2026 depending on type. Blown cellulose and fiberglass are the budget options; closed-cell spray foam is the highest-performance choice.

TypeR-valueMaterial/sfInstalled/sf
Radiant barrierradiant only$0.10-$0.30$0.50-$1.50
Blown fiberglassR-2.5/in$0.40-$0.80$1.00-$2.30
Blown celluloseR-3.5/in$0.50-$1.00$1.00-$2.50
Fiberglass batt (wall)R-3.2/in$0.40-$1.20$1.20-$2.70
Fiberglass batt (attic)R-3.2/in$0.80-$2.00$1.80-$3.80
Mineral wool (Rockwool)R-4/in$1.00-$2.20$2.20-$4.20
Rigid foam boardR-5/in$0.50-$2.00$1.50-$4.00
Open-cell spray foamR-3.5/in$1.00-$1.80$1.50-$3.00
Closed-cell spray foamR-6.5/in$2.00-$3.50$3.00-$5.50

Frequently asked questions

How much does insulation cost in 2026?

Fiberglass batts run $1.50-$3/sf installed. Blown cellulose $1-$2.50/sf. Spray foam open-cell $1.50-$3/sf, closed-cell $3-$5/sf. A 1,500 sf attic top-up to R-49 with cellulose runs $1,500-$3,750.

What R-value do I need?

DOE recommends R-30 to R-49 in attic floors for southern climates and R-49 to R-60 for northern climates. Walls: R-13 to R-21. Floors over crawl: R-19 to R-30. The IECC 2024 climate-zone map sets local code minimums.

Spray foam vs cellulose - which is better?

Closed-cell spray foam delivers the highest R-value per inch (R-6.5/in) and air-seals at the same time, but costs 2-3x cellulose. Cellulose is cheap, dense, and a great attic top-up. Spray foam shines in cathedral ceilings, rim joists, and crawl spaces where moisture matters.

Can I install insulation myself?

Batts and rigid foam are very DIY-friendly. Blown cellulose is doable with a rented blower (often free with material purchase from big-box). Spray foam should always be pro-installed (PPE + cure-time off-gassing).

Do I need a vapor barrier?

Cold climates (zone 5+) often want one on the warm side. Hot-humid (zone 1-2) avoid them — they trap moisture. Mixed climates use a smart vapor retarder (MemBrain). Consult IECC 2024 + IRC for your zone.

Why does the calculator show a price range?

Material brand, attic access, R-value target, prep work (rotted, vermiculite), and pro vs DIY swing the total 30-60%. A range gives an honest planning estimate.

Common mistakes & questions

  • Skip air-sealing first — insulating leaky walls only delays heat loss; air-seal then insulate.
  • Wrong R-value for climate zone — IECC 2024 sets minimums; check your zone (this calculator's state multiplier table includes climate zone).
  • Vapor-barrier direction wrong — warm-side in cold climates; avoid in hot-humid (zone 1-2).
  • Spray foam without HVAC redesign — tightening the envelope without rebalancing HVAC can cause moisture issues.
  • Ask your contractor: air-sealing plan, R-value target, vapor barrier strategy, HERS or blower-door test plan.

When this estimate is wrong

  • Removing old insulation is its own job. Wet, moldy, or rodent-contaminated material has to be vacuumed out and bagged before new insulation goes in — labor and disposal the coverage number doesn't include.
  • Air-sealing should come first. Sealing top-plate gaps, wire and pipe penetrations, and the attic hatch before insulating is what makes the R-value actually perform; adding insulation over leaks under-delivers.
  • Attic access and existing depth affect labor. A low, cramped attic or one already partly filled is slower to work than open, easy-to-reach framing.
  • Moisture and ventilation set the details. Attics need baffles to keep soffit vents clear, and a damp basement or crawl may call for a vapor retarder — skip these and you trade an energy problem for a rot problem.
  • Old wiring can stop the job. Knob-and-tube or damaged wiring found in the cavity typically has to be addressed by an electrician before it's safe to bury it in insulation.
  • Code R-value depends on your climate zone. The target for an attic in a cold zone is well above a mild one, so the "right" amount of material — and the cost — varies by where you live.
  • Spray foam is a specialty line. Open- and closed-cell foam are installed by dedicated crews at a higher rate than batt or blown-in, and closed-cell in particular is a premium.