How many nails do you need per square of shingles?
Asphalt shingles need at least 4 fasteners per shingle, or 6 in high-wind regions and on steep slopes (2018 IRC §R905.2.5, plus the shingle maker's instructions). At roughly 80 shingles per square, that's about 320 nails per square — or about 480 with 6 nails — which works out to roughly 2 to 2½ pounds of roofing nails.
Source: 2018 IRC §R905.2.5 · Verify against your AHJ and the adopted code edition.
A square of roofing covers 100 square feet — about 3 bundles, or roughly 80 three-tab/architectural shingles. Fastening drives the nail count:
- 4 nails per shingle is the standard minimum (IRC §R905.2.5).
- 6 nails per shingle in high-wind regions and on steep slopes, and wherever the manufacturer calls for it — following their instructions is itself a code requirement.
So per square:
- 4 nails × ~80 shingles ≈ 320 nails
- 6 nails × ~80 shingles ≈ 480 nails
That’s about 2 to 2½ pounds of roofing nails per square. Buy a bit extra for the starter course, hip and ridge caps, and the odd miss. Nail length must be long enough to penetrate the deck ¾ inch (or fully, if thinner) — also in §R905.2.5. Editions and amendments vary — verify with your AHJ.
Work it out: the roofing calculator turns a footprint and pitch into roof area, squares, and bundle count — multiply squares by 320 (or 480) for nails.
Sources
- ICC — International Codes (IRC) — 2018 IRC §R905.2.5