Insulation Cost Calculator
Enter your area, R-value, and local price per bag or roll to estimate total insulation cost.
1. Area to insulate
2. Location
3. Insulation type
Your Insulation Estimate
30
bags (30 lb)
13.6"
depth needed
Calculation breakdown
Area: 800 sq ft
Target R-value: R-49
R per inch (Blown-in): 3.6
Depth needed: R-49 ÷ 3.6/inch = 13.6 inches
Units: 800 sq ft ÷ 30 sq ft/unit × 1.10 = 30 bags (30 lb)
How the cost is calculated
- 1.Enter area and R-value → calculator outputs bags or rolls needed.
- 2.Enter your price per bag or roll → material cost = quantity × price.
- 3.Add optional vapor barrier or staples cost → total estimate.
- 4.Cost per sq ft = total ÷ area (compare contractor bids).
2026 US insulation price ranges
| Type | Per sq ft (materials) |
|---|---|
| Fiberglass batts (R-13) | $0.30–$0.60 |
| Fiberglass batts (R-19) | $0.50–$0.90 |
| Blown-in fiberglass (R-38) | $0.80–$1.50 |
| Blown-in cellulose | $0.70–$1.20 |
| Open-cell spray foam | $1.50–$3.00 |
| Closed-cell spray foam | $3.00–$6.00 |
Prices vary by region. Enter your actual price for an accurate estimate.
Frequently Asked Questions
How much does insulation cost?
Fiberglass batts: $0.30–$0.60/sq ft for R-13 (2×4 wall), $0.50–$0.90/sq ft for R-19 (2×6 wall). Blown-in attic insulation: $1.50–$3/sq ft installed. Spray foam: $1.50–$3/sq ft (open cell) or $3–$6/sq ft (closed cell).
How much does it cost to insulate an attic?
A 1,000 sq ft attic to R-38 (12") in blown fiberglass costs $600–$1,500 DIY in materials. Professionally blown-in: $1,500–$3,000 for materials and labor.
What R-value do I need?
R-value requirements depend on your climate zone. Attics: R-38 to R-60. Walls: R-13 to R-21. Crawlspaces: R-19 to R-30. Check ENERGY STAR recommendations for your zip code.
Is blown-in or batt insulation cheaper?
Batt insulation is usually cheaper for walls ($0.30–$0.90/sq ft) since it's a DIY-friendly install. Blown-in is faster for attics and achieves better coverage around obstacles — professionals often blow it in for $1.50–$3/sq ft.