House Wrap Calculator
Calculate rolls of house wrap from your wall area. A standard 9 ft x 100 ft roll covers 900 sq ft; add for overlap at seams and openings.
How this calculator works
House wrap comes in large rolls, and a standard roll covers 900 square feet (9 ft × 100 ft). The calculator divides your total wall area by that coverage and rounds up to whole rolls.
Formula: Rolls = wall area (sq ft) ÷ 900 sq ft per roll, rounded up.
Worked example
A wall section 40 ft long × 10 ft high (400 sq ft):
- Rolls: 400 ÷ 900 = 0.44 → 1 roll
- At $150/roll, that’s $150.00 before accounting for overlap on a full house.
Coverage reference
| Wall area | Rolls (900 sq ft each) |
|---|---|
| 900 sq ft | 1 roll |
| 1,800 sq ft | 2 rolls |
| 2,700 sq ft | 3 rolls |
How to measure
Add up each wall’s length times height for the total area, then add about 10% for the 6-inch seam overlaps — check the waste toggle. House wrap goes on before siding; pair this with the Vinyl Siding Calculator to size the cladding that covers it.
Frequently asked questions
How many rolls of house wrap do I need?
A standard roll is 9 feet by 100 feet, covering 900 square feet. Divide your total wall area by 900 and round up. The calculator does this and adds a waste allowance for the 6-inch overlap house wrap needs at every seam.
How much overlap does house wrap need?
Overlap horizontal seams by 6 inches and vertical seams by 6–12 inches, shingle-style so water sheds downward. This overlap is why you add about 10% to the bare wall area — check the waste toggle to include it.
Do I wrap over or under window openings?
Wrap continuously over the whole wall, then cut an I-shape at each opening and fold the flaps in, so the wrap integrates with the window flashing. Don't leave gaps around openings — that's where most water intrusion starts.
Is house wrap the same as a vapor barrier?
No. House wrap is a weather-resistant barrier that blocks liquid water and air while letting vapor escape, so walls can dry. A vapor barrier stops vapor entirely and goes on a different side of the wall depending on climate. Don't substitute one for the other.
Estimates only. Verify quantities with your supplier before purchasing.