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Insulation R-Value Calculator

Calculate total R-value for multi-layer assemblies, estimate annual heat loss, energy costs, and compare against DOE climate zone recommendations.

Estimates only — actual performance depends on installation quality and air sealing

Climate zone and the area you're insulating

DOE Climate Zone

Assembly Location

Surface Area (sq ft)

Unit System

Add each layer — R-values are additive in series

MATERIAL THICKNESS R-VALUE

Load Assembly Preset

For annual heat loss and savings calculations

Indoor Temp (°F)

Avg Outdoor Temp (°F)

Heating Hours per Year

Energy Cost

Per kWh (electric) or per BTU equivalent

Heating System Efficiency (%)

Heating Fuel Type

Assembly Summary

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Total R-Value

U-Factor—

Layers—

Surface Area—

Zone Rec.—