How it works
The calculator works out the wall area, takes the overlaps off what one roll covers and divides; it then counts seams and fastener rows from the same layout.
Area to wrap = Perimeter × Wall height + Gables (− Openings, if chosen)
Coverage per roll = (Roll width − Horizontal lap) × (Roll length − Vertical lap)
Rolls = ⌈ Area to wrap × (1 + Extra) ÷ Coverage per roll ⌉
Courses = 1 + ⌈ (Wall height − Roll width) ÷ (Roll width − Horizontal lap) ⌉
Vertical seam tape = ⌈ Perimeter ÷ (Roll length − Vertical lap) ⌉ × Wall height
Horizontal seam tape = (Courses − 1) × Perimeter
Cap fasteners = ⌈ Perimeter ÷ Stud spacing ⌉ × (⌈ Wall height ÷ Fastener spacing ⌉ + 1) + ⌈ Gables ÷ (Stud spacing × Fastener spacing) ⌉
⌈ ⌉ means rounding up to whole rolls, seams and fasteners.
How house wrap goes on
DuPont’s guide starts at a bottom corner with the roll plumb, the bottom edge lapping over the sill plate onto the foundation, and unrolls the wrap around the house straight over windows and doors. Where one roll ends and the next starts, the vertical seam overlaps 6–12 in. The next course goes above and laps over the lower one by at least 6 in, so water running down the face never gets behind a seam. The wrap is fastened along the stud lines with cap nails, cap screws or cap staples, 6–18 in apart, and the vertical seams are taped.
Rolls
Wide rolls – 9 ft or 10 ft – cover a single storey in one course, so a one-storey house often needs only one or two rolls. The calculator divides the area by the coverage after laps, which is close to how the rolls are actually used on long walls. On a house with many short walls and gables, the last piece of each roll may be too short to use; round up generously.
Fasteners and tape
Fasteners are counted on every stud line around the perimeter: with studs 16 in on center and fasteners every 18 in on a 9 ft wall, that is 105 stud lines × 7 = 735 cap fasteners for a 140 ft house. Tape is counted for the vertical seams over the full wall height and, as a recommended extra, for the horizontal seams between courses.
Worked example in words
A house is 140 ft around with 9 ft walls and no gables, wrapped with 9 × 150 ft Tyvek HomeWrap over the windows. The area is 1,260 sq ft. One roll covers 8.5 × 149.5 = 1,270.75 sq ft after the 6 in laps, so one roll is enough; the wall is one course with one vertical seam, 9 ft of tape. Fasteners: 1,680 in ÷ 16 in = 105 stud lines, each with 108 ÷ 18 + 1 = 7 fasteners – 735, one box of 2,000.
What is not included
Window and door flashing, flashing tape, sealant and the extra wrap needed at inside corners, wall-to-roof joints and penetrations are not counted. Whether the wall needs a water-resistive barrier, an air barrier or a vapor retarder – and which one – is set by the building code and the wall design.
Worked example
Inputs
- Distance around the house
- 140 ft
- Wall height
- 9 ft
- Gable area
- 0 sq ft
- Subtract windows and doors
- No
- Roll
- DuPont Tyvek HomeWrap 9 ft × 150 ft (1,350 sq ft)
- Horizontal lap
- 6 in
- Vertical lap
- 6 in
- Waste allowance
- 0 %
- Stud spacing
- 16 in
- Fastener spacing on each stud line
- 18 in
- Cap fasteners per box
- 2000
Result
- Wall and gable area
- 1,260 sq ft
- Openings subtracted
- 0 sq ft
- Area to wrap
- 1,260 sq ft
- Coverage per roll after laps
- 1,271 sq ft
- Rolls of house wrap
- 1
- Cap fasteners
- 735
- Boxes of cap fasteners
- 1
- Tape for vertical seams
- 9 ft
- Tape for horizontal seams
- 0 ft
Common mistakes
- Subtracting the windows and then running short. The wrap goes over the openings and is cut in a pattern that folds into the rough opening, so little of it is saved.
- Forgetting the laps. With a 6 in horizontal lap a 9 ft roll covers only 8.5 ft of height, and every place two rolls meet loses another 6–12 in.
- Wrapping with the lower course over the upper one. Water runs down; each upper course has to lap over the course below (shingling).
- Spacing fasteners too far apart or off the studs. DuPont's guide fastens along vertical stud lines, 6–18 in apart.
- Leaving vertical seams untaped. DuPont's guide tapes every vertical seam; untaped seams let air and water through.
Assumptions and limits
- Wall area is the perimeter times the wall height plus any gable area; openings are subtracted only if you choose to.
- Each roll covers its width minus the horizontal lap times its length minus the vertical lap. Courses and roll ends are not planned piece by piece.
- Rolls are unrolled around the house in horizontal courses; vertical seams are counted where one roll ends and the next starts, running the full wall height.
- Cap fasteners are counted on each stud line around the perimeter, from the bottom to the top of the wall, plus the gable area at the same grid. Openings do not reduce the count.
- Seam tape is counted for walls only; gable seams, flashing tape and the tape for window details are extra.
Frequently asked questions
How much house wrap do I need?
Multiply the distance around the house by the wall height, add the gables, and divide by what one roll covers after the overlaps. A 9 × 150 ft roll of Tyvek HomeWrap is 1,350 sq ft, but with a 6 in lap on each edge it covers 8.5 × 149.5 = 1,270.75 sq ft.
How much should house wrap overlap?
DuPont's installation guide asks for the upper layer to overlap the lower one by at least 6 in, and for vertical seams to overlap by 6–12 in. Other wraps have their own guide; use your maker's laps.
How far apart should house wrap cap nails be?
DuPont's guide fastens Tyvek along the vertical stud lines, no closer than 6 in and no farther than 18 in apart, with cap nails, cap screws or cap staples. On walls with studs 16 in on center that is about 7 fasteners per stud line on a 9 ft wall.
Do I subtract windows and doors?
Usually not. DuPont's method unrolls the wrap straight over windows and doors and then cuts it at each opening, folding flaps into the rough opening. Subtracting openings makes sense only for very large openings such as garage doors – use the yes option for those.
What sizes does Tyvek HomeWrap come in?
DuPont's guide lists HomeWrap in 3 × 100, 3 × 165, 5 × 200, 9 × 100, 9 × 150, 10 × 100 and 10 × 150 ft rolls. The 9 ft and 10 ft rolls cover a typical storey in one course.
Sources
- DuPont Tyvek Water-Resistive and Air Barriers (WRB) and DuPont Self-Adhered Flashing Products Installation Guidelines (43-D100976-enNA-1225) — DuPont. Tyvek HomeWrap rolls 3 × 100, 3 × 165, 5 × 200, 9 × 100, 9 × 150, 10 × 100 and 10 × 150 ft; "Overlap all vertical seams by 6"– 12""; "Upper layer of Tyvek WRB should overlap bottom layer by a minimum of 6""; fasteners "no closer than 6" and no farther than 18" on vertical stud lines"; Wrap Cap staples and nails 2,000 per box; tape all vertical seams, horizontal seams recommended.
- NIST Handbook 44, Appendix C – General Tables of Units of Measurement — National Institute of Standards and Technology. Exact unit definitions: 1 in = 2.54 cm, 1 yd³ = 27 ft³, 1 US gal = 231 in³, 1 lb = 0.45359237 kg.
Method reviewed November 5, 2026