House Wrap Calculator — ft, rolls, cost
How to use this calculator
Type building perimeter and wall height, a single wall, or net ft² already taken off the plans. Gables get added on top, doors and windows come out, then the calc adds shingle-lap overlap and a waste %. Pick a preset to load a real house footprint.
Seam tape — 2–3″ tape for all horizontal and vertical seams, ~165 ft per roll.
Fasteners — cap nails or cap staples, ~1 per ft² of wrap, 1000 per box.
Cost — per roll of wrap, tape, and fastener box.
Saved Calculations
| Time | Method | Net ft² | Rolls | Cost |
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How to Calculate House Wrap
House wrap (a weather-resistive barrier, WRB) is installed over exterior sheathing before cladding to shed bulk water and reduce air infiltration. Take the building perimeter × wall height for gross wall area, add triangular gable areas (½ × base × peak height), then deduct doors (~20 ft² each) and windows (~15 ft² each). The overlap factor adds material consumed by the shingle-lapped horizontal and vertical seams, and the waste allowance covers cuts at corners, around flashed openings and torn courses.
Formulas
Gross area = perimeter × height + gable areas. Net area = gross − openings. Overlap factor = roll area ÷ [(roll width − horiz. overlap) × (roll length − vert. overlap)]. Adjusted area = net × overlap factor × (1 + waste%). Rolls = ⌈adjusted area ÷ roll coverage⌉. Seam tape length ≈ horizontal seams + vertical butt joints; fasteners ≈ 1 cap nail or cap staple per ft².
Roll Sizes
Common sizes: 3′×100′ (300 ft²), 5′×100′ (500 ft²), 9′×100′ (900 ft²), 9′×150′ (1,350 ft²), 10′×100′ (1,000 ft²). For standard 8′ walls, a 9′ or 10′ wide roll wraps the full story height in one course with overlap top and bottom; narrower 3′ rolls run multiple horizontal courses with a 6″ shingle lap. Pair this with the wall insulation calculator and vapor barrier calculator to complete the wall assembly.
FAQ
How much overlap? Minimum 6″ horizontal (shingle-lap so upper course laps over lower), 6–12″ at vertical butt seams per manufacturer specs; double the lap over inside corners. How many fasteners? Roughly 1 cap nail or cap staple per ft² of wrap, spaced 12–18″ along studs and 6″ at seams. Do I need seam tape? Yes — tape all horizontal and vertical seams, tears and penetrations with manufacturer-approved tape for a continuous air and water barrier. For roof and attic assemblies use the roof insulation calculator; for an air-seal upgrade compare spray foam.
On install day
Three things that blow the takeoff. Inside corners — IRC R703.2 and most manufacturers want the wrap to lap continuously around inside corners by a full 12″; if you cut at the corner you create a vertical seam that has to be taped and counter-flashed. Window flashing sequencing — the wrap goes over the sill flashing and behind the jamb/head flashing (reverse-shingle), not the other way around; getting it backwards is the #1 callback on a WRB job. UV exposure — Tyvek, Typar and most spunbonded wraps are warranted for ~120 days of exposure; if cladding is delayed past that, expect chalking and demand a re-wrap. Budget $0.35–0.75/ft² installed for the wrap itself in 2025 USA (material $0.10–0.20/ft², the rest is labor + tape + caps); a single-story 1,500 ft² ranch typically runs $400–900 in wrap and accessories. Pair this with a finish takeoff and the wall insulation calculator to close out the envelope.
