Vapor Barrier Calculator

Estimate the vapor barrier or vapor retarder material needed for your project. Enter dimensions and overlap to compare rolls needed and total cost for 6-mil polyethylene, reinforced poly, kraft-faced batts, and smart vapor retarders.

Length (ft)

Width (ft)

Overlap (inches)

Waste Factor (%)

Material Pricing (edit to match local rates)

6-mil Poly ($/roll)

Reinforced Poly ($/roll)

Kraft-Faced ($/roll)

Smart Retarder ($/roll)

Seam Tape ($/roll)

Staples ($/box)

Total Coverage Needed

1122 sq ft

1000 sq ft base + overlap & waste

Best Value

6-mil Polyethylene

2 rolls

Lowest Total Cost

$158.00

incl. tape & staples

Barrier Type	Material Needed	Total Cost
6-mil PolyethyleneBest value	2 rolls (10x100 ft) + 2 tape	$158.00
Reinforced Poly	2 rolls (6x100 ft) + 2 tape	$218.00
Kraft-Faced Batts	13 rolls (15 in x 32 ft)	$390.00
Smart Vapor Retarder	2 rolls (9.2x114 ft) + 2 tape	$378.00

Recommended: 6-mil Polyethylene at $158.00For 1000 sq ft of coverage (with 6" overlap and 10% waste), 6-mil Polyethylene provides the lowest total material cost. Be sure to seal all seams with vapor barrier tape and staple at 12-16 inch intervals along framing members.

Material quantities are estimates based on standard roll sizes and typical overlap/waste. Actual needs vary by installation method, room layout, and local code requirements. Kraft-faced batts provide a vapor retarder only and may not meet all local vapor barrier code requirements. Consult local building codes and a qualified contractor for your specific application.