Inputs
White theme
Example scenarios
| Scenario | Deck area (ft²) | Supports (in) | Edge / Field (in) | Across | Overage % | |
|---|---|---|---|---|---|---|
| Standard tract roof | 2000 | 24 | 6 / 12 | Long | 10 | |
| Coastal high-wind | 2000 | 16 | 4 / 6 | Long | 12 | |
| Complex roof, steeper pitch | Use L×W×Pitch | 24 | 6 / 6 | Short | 15 |
Formulas used
- Deck area: If entering directly, use A. Otherwise, A = L × W × √(1 + (pitch/12)²).
- Panels: Panel area P = Lp × Wp. Panels = ceil( A × (1 + overage%) / P ).
- Supports: Across-support dimension Sa (in). Support spacing s (in). Support lines Ns = floor(Sa / s) + 1. Interior lines Ni = max(Ns − 2, 0).
- Perimeter nails per panel: For each edge length E, nails = floor(E / e) + 1. Sum all four edges and subtract 4 to avoid double-counted corners.
- Field nails per panel: Nails per interior line = floor(Salong / f) + 1. Field nails = Ni × nails per line.
- Total nails: Nails per panel Np = perimeter + field. Total = ceil( Np × Panels × (1 + overage%) ).
- Boxes: Boxes = ceil( Total / nails per box ).
This tool is an estimator; verify local requirements and manufacturer schedules.
How to use
- Select Area mode: total deck area, or compute by length, width, and pitch.
- Set panel size and whether the long or short side spans across supports.
- Pick support spacing, then edge and field nail spacing or a preset schedule.
- Adjust overage to cover waste, misses, or box breakage. Set nails-per-box.
- Click Calculate. Review panels, nails per panel, total nails, and boxes.
- Export a summary using CSV or PDF for records, sharing, or procurement.
FAQs
It indicates which panel side spans across rafters or trusses. That dimension determines the number of support lines, which sets how many interior nail rows exist.
No. The calculator sums nails along each edge and subtracts four to avoid double-counting the four corner nails.
Yes. Overage increases both panel count and nail count to cover waste, losses, or tighter fastening needed on site.
Absolutely. Packaging varies with coils, strips, or bulk. Enter your supplier’s packaging count to estimate required boxes more accurately.
Schedules vary by code, wind exposure, and sheathing thickness. Use this as a planning estimate and verify final requirements with your authority and manufacturer.
Results
Live after you calculate
Panels needed
—
Panel area — ft²
Nails per panel
—
Edge — · Field —
Total nails (with overage)
—
Deck area — ft²
Boxes required
—
Nails per box —
| Parameter | Value | Unit |
|---|