Project Inputs
White ThemeAll internal math in ft².
Add allowance for cuts, layout, damage.
Typical 16–24; adjust to product.
Extra for J-channel, corners, starter.
Panel Setup
ft
Common: 12, 12.5, 16 (ft) or 3.66, 4.88 (m).
in
Visible height per course (e.g., 4, 5, 6, 7, 8 in).
Rough planning number; adjust to specs.
Walls
| # | Width | Height | Actions |
|---|
Starter strip uses sum of wall widths only.
Gables (Triangles)
| # | Base Width | Height | Actions |
|---|
J-channel adds along both rakes of each gable.
Openings (Subtract)
| # | Width | Height | Actions |
|---|
Window and door perimeters add to J-channel length.
Accessories & Corners
ft
ft
Typical 10' pieces.
ft²/roll
Allowance for laps and mitering.
Example Data Table — Coverage per Panel
Assumes panel length 12.5 ft. Exposure is the visible course height.
| Exposure (in) | Coverage per Panel (ft²) | Panels per Square |
|---|
Results
Net Area
0.00 ft²
Squares
0.00
| Item | Value |
|---|
Formula Used
- Wall area = Σ (width × height)
- Gable area = Σ (0.5 × base × height)
- Openings area = Σ (width × height)
- Net area = (Wall + Gable − Openings)
- Adjusted area = Net area × (1 + Waste/100)
- Coverage per panel = Panel length × Exposure/12
- Panels needed = ⌈Adjusted area ÷ Coverage per panel⌉
- Cartons needed = ⌈Panels needed ÷ Panels per carton⌉
- Squares = Adjusted area ÷ 100
- J‑channel length ≈ Σ opening perimeters + Σ 2×gable rake length
- Starter strip length ≈ Σ wall widths
- Corner pieces each = ⌈Corner height ÷ Corner piece length⌉
All length inputs converted to feet; areas computed in ft². Metric inputs are converted to US customary for calculations, then values are displayed.
How to Use
- Choose units, set waste, panel length, exposure, and carton size.
- Add each wall’s width and height. Add gables if applicable.
- Add windows and doors as openings to subtract their area.
- Set corner counts and heights; adjust trim and wrap options.
- Click Calculate. Review net area, squares, panels, cartons, and trims.
- Download a report via Download CSV or Download PDF.
Always verify against manufacturer specifications and local codes before ordering.
FAQs
One square equals 100 square feet of wall surface. The calculator reports total squares after waste adjustments for planning and purchasing.
Exposure is the visible course height. Typical profiles are 4–8 inches. Larger exposure covers more area per panel but may affect look and wind rating.
Ten percent is common. Increase for complex elevations, many openings, steep gables, or diagonal layouts. Review layout to refine waste allowance.
Enter counts and corner height. The tool divides each corner height by the selected piece length, rounding up to whole pieces per corner.
No. Enter only wall and gable siding surfaces. Soffit and fascia are separate systems; this calculator estimates siding and main trims.
Yes. Use the CSV or PDF buttons to download a formatted report that includes inputs, areas, trims, and quantities. Attach to quotes or purchase requests.
Counts are planning estimates. Confirm coverage, carton size, and accessory yields with the specific product data sheet before final ordering.