House Wrap Calculator
Estimate house-wrap rolls and purchased membrane coverage from building perimeter, wall height, opening deductions, overlap allowance and roll dimensions.
Default project preview
2 rolls
Gross wall area
1,620 ft²
Opening deductions
260 ft²
Order area
1,564 ft²
Coverage per roll
900 ft²
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Exterior wall perimeter
Enter this project assumption in ft. The current imperial default is 180 ft.
Average wall height
Enter this project assumption in ft. The current imperial default is 9 ft.
Door and window area
Enter this project assumption in ft². The current imperial default is 260 ft². Minimum: 0.
Overlap and waste allowance
Enter this project assumption in %. The current imperial default is 15 %. Minimum: 0. Maximum: 50.
Roll width
Enter this project assumption in ft. The current imperial default is 9 ft.
Roll length
Enter this project assumption in ft. The current imperial default is 100 ft.
Price per roll
Enter this project assumption in per roll. The current imperial default is 165 per roll. Minimum: 0.
How to read the outputs
Gross wall area
perimeter × wall height. Default preview: 1,620 ft².
Opening deductions
doors and windows. Default preview: 260 ft².
Order area
15% overlap and waste. Default preview: 1,564 ft².
Coverage per roll
entered roll dimensions. Default preview: 900 ft².
Surplus coverage
after roll rounding. Default preview: 236 ft².
Material allowance
rolls × entered price. Default preview: $330.00.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Net wall area = perimeter × wall height − openings. Order area includes overlap and waste. Rolls = round up (order area ÷ roll area).
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 29, 2026
This calculator estimates house-wrap rolls from exterior wall area, openings, roll coverage and lap allowance. It supports ordering but does not design the complete water-resistive barrier, drainage plane or air barrier.
Calculation steps
- 1Measure all exterior wall elevations, including gables.
- 2Subtract large openings only.
- 3Add overlap, corner and repair allowance.
- 4Divide by actual roll coverage and round upward.
Worked numerical example
A 2,600 ft² gross wall area with 350 ft² of openings leaves 2,250 ft². At 12% lap and cutting allowance, order coverage is 2,520 ft²; with 900 ft² per roll, purchase three rolls.
Purchasing and rounding
Roll area is nominal; effective coverage decreases with horizontal and vertical laps. Seam tape, cap fasteners and flashing components are separate quantities.
Interpret the result
Unused roll area can be valuable for complex corners and repairs. A low roll count should be checked against gables and wall returns.
Page-specific assumptions
- Continuous exterior wall coverage.
- Openings are flashed separately.
- Roll dimensions match the selected product.
- Allowance includes required laps.
Common mistakes
- Omitting gable walls.
- Using floor area.
- Installing reverse laps.
- Treating wrap alone as every control layer.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
House Wrap Calculator questions
Should window and door openings be deducted?+
Yes for a closer area estimate, although flashing and wrapping into openings can use some of that material.
Does this calculate tape and flashing?+
No. Those quantities depend on seams, openings, penetrations and the selected weather-resistive barrier system.
Why is overlap included?+
Horizontal and vertical seams, corners and repair patches require more material than the net wall area.