Duct Insulation Calculator
Ducts running through an attic or crawlspace can lose 20 to 30% of the air you paid to heat. Enter your duct run to size the wrap and tape.
Your project
Covers cuts, compression and odd bays. 10% is the usual default.
Your results
- Wrap needed
- 207 sq ft
- Wrap width to buy
- 41 in
- R-value
- R-6
- Foil tape required
- 78 ft
- Estimated material cost
- $197
- Annual savings estimate
- $72
Circumference plus 3 in for the seam overlap
Seams every 4 ft plus longitudinal seam
Typical for ducts in unconditioned space
Estimates use typical US material and labor pricing. Confirm quantities against the coverage chart on the bag before you buy.
Gear for this job
Duct Insulation Wrap
Frost King CF55 Foil Backed "No Itch" Natural Cotton Duct Wrap, 12-Inch x 1-Inch x 15-Feet
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US Energy Products R-8 HVAC Duct Wrap Insulation Reflective Double Sided Foam Core (Class 1-A ASTM FIRE Rated) (AD5 1/4INCH Thick) 4FT X 50FT (200SQFT)
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Duct Insulation, 1-1/2In x 48In x 25Ft
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Foil Tape Hvac Insulation
Romeda Aluminum Foil Tape, 2 inch x 65 Feet Foil Tape (3.9 mil), Silver Insulation Adhesive Metal Tape, High Temperature Heavy Duty HVAC Tapes for Ductwork, Dryer Vent, HVAC
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Aluminum Foil Duct Tape Heavy Duty Waterproof, Premium Silver Metal HVAC Heat Tapes (2"*65Feet,3.9mil), High Temperature, Dryer Vent Insulation Tape for Ductwork, Ducting, Sealing, Patching, Furnace
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ETERART Aluminum Foil Duct Tape, High-Temp Seal for HVAC,2" x 20Yds | Heavy-Duty, Dryer Vents & Insulation, Stops Air Leaks & Resists Extreme Heat for Home Repair, Silver, easy to apply, durable
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Reflective Attic Insulation Roll
AtticFoilㅤ – SuperPerf Radiant Barrier – 45” Wide / 1500 sq ft | Tearproof Breathable Lay-Over Foil Insulation with Large Perforations–Designed for Use Directly Over Attic Insulation
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Double Bubble Foil Insulation Roll 24" x 125' Radiant Barrier | Reflective radiant barrier for attics, roofs, walls, garages & HVAC. Aluminum foil blocks radiant heat;.
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Ultra Heavy Duty 10mm Reflective Insulation Roll - Premium Foam Core Radiant Barrier for Energy Conservation -Commercial Grade Soundproofing Thermal Shield for Indoor and Outdoor (24" X 25')
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How this calculator works
- Outer circumference = π × (duct diameter + 2 × wrap thickness)
- Wrap area = circumference (ft) × duct length × (1 + waste %)
- Tape = duct length × 1.3
Frequently asked questions
What R-value should duct insulation be?
R-6 is the common minimum for ducts in unconditioned space, and R-8 is required in hot or cold climate zones. Ducts inside the conditioned envelope need only sealing.
Should I seal ducts before insulating?
Always. Mastic or foil tape on every joint first — insulating over leaky ducts just hides the loss.
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Wrap needed
207 sq ft