Insulation installation cost calculator
Build the whole job from the parts you actually pay for — material, labor, air-sealing, removal and access — then add a contingency so a surprise does not blow the budget.
Calculator
A 1,000 ft² job at $1.20/ft² plus labor, air-sealing, removal and access is about $2,420.00 with 10% contingency. Enter the prices from your own quotes.
A real insulation quote is never just material. The number that surprises homeowners is the sum of the add-ons — air-sealing, tearing out the old stuff, and getting a crew into a low attic or a tight crawlspace. This tool itemizes the job the way a contractor builds it, then applies a contingency so the odd extra hour or an extra bag does not put you over. Enter every price from your own bids; the tool holds none.
Formula
total = (area × $/ft² + labor + air‑sealing + removal + access − discount) × (1 + contingency)
Material is area × $/ft²; everything else is a flat dollar figure from the quote. The contingency is applied to the whole subtotal, credits included — that is deliberate: overruns scale with the size of the job, not just the material.
Worked example
1,000 ft² at $1.20/ft² material, $800 labor, $200 air-sealing, no removal, no access charge, no discount, 10% contingency:
(1,000 × $1.20 = $1,200) + $800 + $200 = $2,200$2,200 × 1.10 = $2,420
Add a $400 tear-out of old, matted insulation and the subtotal becomes $2,600 → $2,860 with contingency. That single line is why removal deserves its own box.
The line items crews price separately
Ask every bidder to break the quote into these so you are comparing like with like:
- Air-sealing. The cheapest performance you can buy — sealing top plates, penetrations and the attic hatch before insulating. Often quoted as a flat add-on; put it here.
- Removal. Old, wet, rodent-fouled or over-deep insulation has to come out first. Vacuum-out plus haul-off is priced by the square foot or as a lump — use the removal & replacement tool for a detailed split.
- Access. A knee-high attic, a belly-crawl crawlspace, or two-story exterior walls slow a crew down. Some bids bury this in the $/ft²; make them name it.
- Contingency. 10% is a sensible default on a clean job; push it to 15–20% on an old house where you cannot see behind the finishes.
This is a planning estimate from your numbers, not a bid or a contract. Get itemized written quotes from licensed, insured insulation contractors before you commit.
Reference table
| Material | Typical installed $/ft² |
|---|---|
| Fiberglass batt | $0.80–$2.40 |
| Blown-in (fiberglass / cellulose) | $1.00–$2.80 |
| Cellulose (dense-pack) | $1.00–$2.60 |
| Mineral wool (Rockwool) | $1.40–$4.00 |
| Open-cell spray foam | $1.00–$2.50 |
| Closed-cell spray foam | $1.50–$4.50 |
| Rigid foam board | $1.50–$3.50 |
| Radiant barrier | $0.30–$0.80 |
Labeled planning bands (installed = material + labor), not a live price list — a sanity guide only. You enter the real price from your own quotes.
Frequently asked questions
How much does it cost to insulate a house?
There is no one number — it is the sum of area × your $/ft² plus labor, air-sealing, any removal and access, times a contingency. A single 1,000 ft² attic often runs around $2,000–3,000 installed; a whole-house project is many such line items added up. Enter your own quoted prices.
What contingency should I use?
10% is a reasonable default. Raise it to 15–20% on older homes, hard access, or where old insulation and hidden conditions could add work once the crew opens things up.
Should air-sealing be a separate line?
Yes — it is separate work and the highest-value dollars in the job. Keep it out of the material $/ft² so you can see and compare it across bids.
Why apply the contingency to the whole subtotal?
Because overruns scale with the size and complexity of the job, not just the material. Applying it to the full subtotal (after any credit) keeps the buffer proportional.
Does this replace a contractor quote?
No. It is a planning estimate to help you read and compare quotes. Always get itemized written bids from licensed, insured insulation contractors.