House Wrap Rolls Calculator
Estimate rolls of house wrap from the building perimeter and wall height, with an overlap allowance and roll coverage.
How it works
wall area = perimeter × height · rolls = ceil( wall area × (1 + overlap%) ÷ coverage per roll )
House wrap covers the walls, so the area is the building perimeter times the wall height. Vertical seams overlap by about six inches and horizontal seams shingle-lap, so the wall area is inflated roughly 10% before dividing by the roll’s coverage — a common 9 ft × 100 ft roll is 900 square feet. Wrapping straight over window and door openings and slicing them out afterward is faster and wastes little.
Worked example
A 40 × 40 ft house has a 160 ft perimeter; at 9 ft walls that is 1440 sq ft. Adding 10% gives 1584 sq ft, and at 900 sq ft per roll that is 2 rolls of 9 ft × 100 ft house wrap.
Frequently asked questions
Do I subtract windows and doors?
No — wrap over them and cut the openings out afterward with an I-cut or modified-I so the flaps can be folded in and taped. That is why openings are left in the area and only a small overlap allowance is added.
How much should seams overlap?
Vertical seams lap about 6 inches and are taped; horizontal seams shingle-lap 2 to 6 inches so water sheds outward. The 10% default covers those laps on a simple rectangle — add more for a cut-up footprint with many corners.
Which way does house wrap go on?
Printed side out, from the bottom up so each higher course laps over the one below like shingles, and taped at all seams. Getting the lap direction wrong funnels water behind the wrap.
Related calculators
Estimates only — add for waste and confirm against local building codes and supplier specs.