All insulation calculators
Free, instant, no signup. Each one runs in your browser and gives you the exact unit you order in — bags, batts, board feet or dollars.
Insulation AreaWork out the square feet of insulation for a room, attic or wall, with doors and windows deducted, ready to turn into bags or batts.Open R-ValueCalculate the R-value of any insulation thickness, see the DOE recommended R-value for your climate zone, and find how many more inches you need.Open Attic InsulationR-49 takes about 14 in of cellulose or 19 in of blown fiberglass. Enter attic size and current depth for bags, inches to add and DIY vs installed cost.Open Wall InsulationCalculate wall insulation for any stud wall: net square footage, number of stud bays, batts required and estimated cost.Open Blown-In BagsA 1,500 sq ft attic at R-49 takes ~125–135 bags of 19 lb cellulose or 40–45 of fiberglass. Get bags, depth, coverage per bag and cost.Open Batt QuantityAn R-13 bag covers about 88–106 sq ft, an R-30 bag 40–58 sq ft. Enter your area and batt size for pieces, bags and cost per square foot with waste.Open Spray Foam Board FeetBoard feet = area × inches of foam. Get board feet, R-value (open-cell R-3.7/in, closed-cell R-6.5/in), DIY kits needed and a contractor estimate.Open Insulation CostMost 1,200 sq ft attics cost $1,700–$3,200 installed at R-49. Estimate cost per sq ft and total for batts, blown-in, foam board or spray foam, DIY or pro.Open Crawlspace InsulationCompare insulating crawlspace walls (encapsulated) with the floor above (vented): wall and subfloor area, vapor barrier square feet and installed cost.Open Basement InsulationBasement walls need R-10 to R-15 continuous: 2 in of XPS gives R-10. Enter perimeter and height for 4x8 foam sheets, furring strips and installed cost.Open Garage Door InsulationCalculate how many insulation panels or kits your garage door needs, the R-value you'll gain and what it costs.Open Rim Joist InsulationCalculate rim joist insulation: bay count, rigid foam cut sizes, spray foam board feet and cost for your basement band joist.Open Duct InsulationFree duct wrap calculator: enter duct size and run length for square feet of R-6 or R-8 wrap, foil tape and cost. Attic ducts need R-8 under the 2021 IECC.Open Floor InsulationCalculate floor insulation over a crawlspace or unheated garage: joist bays, batt count, R-value and installed cost.Open Rigid Foam BoardCalculate how many sheets of EPS, XPS or polyiso rigid foam board you need, the R-value of the layers and total cost.Open Radiant BarrierRadiant barrier foil costs about $0.22/sq ft of roof deck in material. Get rolls, staples, DIY cost and expected cooling savings (3–12%) by climate zone.Open Pipe InsulationEnter pipe size and run length to get how many 6 ft foam sleeves to buy, with fittings, tape and cost — for hot water lines and pipes at risk of freezing.Open Water Heater BlanketSize a water heater insulation blanket by tank capacity, see the R-value you need and the annual energy savings it should return.Open SoundproofingTreat 15–25% of wall area for most rooms, 35% for studios. Enter room size for acoustic panel count, mineral wool batts and the STC range you can expect.Open Vapor BarrierGet vapor barrier square feet for a crawlspace, wall or floor with 12 in overlaps and 15% for laps, plus seam tape, roll runs and cost for 6, 10 or 20 mil.Open Ventilation & BafflesCalculate attic ventilation: required net free area, soffit and ridge vent split, and how many rafter baffles to buy.Open Energy Savings & PaybackEstimate the annual energy savings, payback period and 10-year return from an insulation upgrade, including rebates.Open Heat Loss (BTU)Heat loss = area × temperature difference ÷ R-value. Get BTU/hr through any wall, attic or window, before and after insulating, and the yearly fuel cost.Open U-Value ConverterR-value is 1 ÷ U-value. Convert U to R and back in imperial or metric (RSI = R × 0.1761), and add up the total R-value of a layered wall or roof.Open Insulation Removal CostOld attic insulation removal runs $1–$2.25 per sq ft — about $1,200–$2,700 for 1,200 sq ft. Compare DIY vacuum rental, bags and disposal with a contractor.Open Labor HoursEstimate how many labor hours an insulation job takes, how long it is with your crew size, and what the labor costs.Open Project TotalAdd up a whole-house insulation project: attic, walls, floors, air sealing, removal and labor into one total estimate.Open Shed InsulationInsulation for a shed: wall, roof and floor area separately, how much material at your R-value, and what to do if the shed has no stud cavity.Open Pole Barn InsulationInsulation for a post-frame pole barn or pole shed: wall and roof area, girt bay counts, and the ceiling-vs-roofline choice that sets how much you need.Open Garage InsulationInsulation for an attached or detached garage: wall, ceiling and door areas separately, with the shared house wall picked out as the one that matters.Open Metal Building InsulationInsulation for a steel building or metal shed, sized around the thing that actually fails: condensation on the inside of the panel, not R-value.Open Van InsulationInsulation for a van or camper conversion, where thickness is rationed: area by surface, R per inch compared, and the thermal bridging that undoes it.Open How Much InsulationHow much insulation a house needs, from floor area and storeys: attic, wall and floor square footage, bags or batts, and the R-value each should reach.Open Roll QuantityA 15 in × 32 ft roll covers 40 sq ft, so 1,000 sq ft with 10% waste needs 28 rolls. Get rolls by area and by cut length, with the offcut waste per roll.Open Attic Insulation CostEstimate attic insulation cost by size and climate zone: material, labor, removal of old insulation, air sealing and baffles. Pro vs DIY, cost per sq ft.Open Blown-In Insulation CostBlown-in insulation cost for an attic or closed walls (drill-and-fill): bags, R-value, contractor vs DIY price and cost per sq ft, fiberglass or cellulose.Open Spray Foam vs Fiberglass CostCompare the installed cost, R-value and yearly heat loss of fiberglass batts, open-cell and closed-cell spray foam for the same wall or roof, with payback.Open Crawl Space Encapsulation CostCrawl space encapsulation cost: liner by mil, wall insulation, dehumidifier, vents, sump and cleanup. A 1,000 sq ft crawl runs ~$4,600–$9,200.Open Cellulose InsulationCellulose bags for any attic R-value from the 19 lb bag chart (R-49 = 12 sq ft per bag), how deep to blow it, and dense-pack bags for walls.Open Cathedral Ceiling InsulationR-value that fits in cathedral ceiling rafters — vented batts, closed-cell, flash-and-batt, open-cell — vs your zone's code R, IRC unvented rules, cost.Open Reverberation Time (RT60)Sabine RT60 calculator: enter room size, measured and target reverberation time, and panel NRC to get the absorption and number of acoustic panels needed.Open Wall Assembly R-ValueWhole-wall R-value with the studs counted: cavity batts, exterior foam, drywall, sheathing and air films, by ASHRAE's parallel-path method.Open Insulation ThicknessHow thick insulation must be for an R-value: pick the material, enter the target R, and get inches, centimetres and the smallest cavity it fits.Open Polyiso R-ValuePolyiso R-value by thickness: roof LTTR R-5.7/in, foil-faced wall board R-5.6 to 6.9/in, layers, sheets and the thickness for a target R.Open ROCKWOOL InsulationROCKWOOL Comfortbatt calculator: batts and bags for your wall or ceiling, R-value and thickness for wood or steel studs, from the product data sheet.Open Attic Hatch InsulationInsulate an attic hatch to match the attic: rigid foam layers for your zone's R-value, sheets to buy, weatherstrip and the loose-fill dam height.Open R-13 InsulationR-13 fiberglass is 3.5 in thick and fills a 2×4 wall. Enter your wall area for bags and batts at real bag coverage, plus R-13 vs R-15 vs R-19.Open R-19 InsulationR-19 fiberglass is 6.5 in thick. Get bags, batts and rolls for your area, where R-19 fits, and why it drops to about R-18 in a 2×6 wall.Open R-30 InsulationHow thick is R-30 insulation? 10.25 in (R-30C 8.25 in). Attic insulation calculator: bags and batts for your area, and whether R-30 meets your zone.Open R-38 InsulationR-38 batts are 12 to 12.5 in thick (R-38C 10.25 in). Get bags and batts for your attic and how much more you need for R-49 or R-60.Open Dew PointDew point from temperature and humidity, plus the inside surface temperature of a wall or window and whether condensation will form on it.Open CaulkHow many tubes of caulk you need: enter the joint length, width and depth or a corner bead, pick the tube size, and get tubes, feet per tube and ounces.Open BTU CalculatorHow many BTUs do I need? Room air conditioner size from the ENERGY STAR chart by square feet, adjusted for sun, people and a kitchen, with tons.Open Whole-House Insulation CostCost to insulate a house: enter square feet, stories and foundation for attic, wall and crawlspace cost at 2026 rates, adjusted for your state's labor.Open CFM CalculatorCFM calculator: airflow for a room from its volume and air changes per hour, bathroom fan size by HVI's rules, and ASHRAE 62.2 kitchen and bath minimums.Open Duct Size CalculatorDuct size calculator: round duct diameter for any CFM at your friction rate, the next standard size, air velocity and rectangular equivalents.Open Dehumidifier Size CalculatorDehumidifier size calculator: pints per day for a basement, crawl space or room by square feet and how damp it is, from ENERGY STAR's sizing chart.Open Whole House Fan CalculatorWhole house fan calculator: CFM for your square footage and ceiling height, Title 24's 1.5 CFM per sq ft minimum, and the attic vent area you need.Open
Insulation gear worth owning
The tools and materials that show up on almost every insulation job.
Aimee’s Workshop Attic Anchor - Insulation Ruler Depth Markers for Blown-in Insulation 30 Pack, 24 Inch Heavy Cardstock
$29.98
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Owens Corning R-19 Unfaced Fiberglass Insulation 77.5 Sq.ft (15 in x 93 in) 1 Batt
$69.99
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Spray Foam Insulation Kit, 12 Pack x 30 oz, Expanding Foam Sealant Spray
$214.99
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3M Particulate Disposable Respirator 8210, N95, Pack of 20, NIOSH APPROVED
$22.89
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Pangda 10 Pack Insulation Removal Vacuum Bags Heavy Duty 75 Cu ft,Black
$95.99
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PT199 Natural Gas Leak Detector with Audible & Visual Alarm, Portable Gas Sniffer to Locate Combustible Sources Like Methane, Propane for Home(Includes Battery x2)-Orange
$22.99
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Prices as of Oct 11, 2026, 4:41 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.
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Attic insulation
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