Project & Siding Settings
Choose feet or meters
Switch anytime; all results update live.
Typical: 5–15% depending on complexity.
ft²
Shingle/siding manufacturer box coverage.
$
Used for budget estimation.
ft
Length along the wall (e.g., 12 ft).
ft
Height covered per course (e.g., 0.75 ft = 9 in).
Walls & Gables
| Label | Width | Height | Has gable? | Gable height | Openings area | Net area | Action |
|---|
Net area = width×height + 0.5×width×gableHeight − openings.
Formula used
- Rectangular wall area = width × height
- Gable area (triangle) = 0.5 × base × gableHeight (base equals wall width)
- Net wall area = rectangular + gable − openings (not less than zero)
- Total gross area = Σ(net wall areas)
- Waste-adjusted area = total gross × (1 + waste%/100)
- Boxes needed = ceil(waste-adjusted area ÷ coverage per box)
- Courses needed per wall ≈ ceil(height ÷ exposure); Panels per course ≈ ceil(width ÷ panelLength); Panels ≈ courses × panelsPerCourse
All formulas follow basic geometry and typical siding coverage conventions.
How to use this calculator
- Select your units, waste factor, coverage per box, and costs.
- Add a wall for each façade. Toggle Has gable? if applicable.
- Enter openings area for windows/doors on that wall.
- Results update automatically. Check totals, boxes, panels, and budget.
- Export your results: CSV for spreadsheets or PDF for sharing.
FAQs
Simple rectangular homes often use 5–7%. Complex elevations, many cuts, or premium patterns can require 10–15% or more. Local installer guidance is best.
Measure each window/door width×height and sum them. Enter the total for that wall. The calculator subtracts openings from the wall’s gross area.
Pick feet or meters at the top. You can switch anytime; the tool converts and keeps your values consistent across all inputs and outputs.
If openings exceed rectangular+gable area, the net is clamped to zero to prevent unrealistic totals. Check your measurements in that case.
Panel counts are estimates using exposure and panel length. Actual layout may vary with starter strips, overlaps, pattern, and manufacturer guidelines.
Example data
Click “Load example” above to populate rows.
| Label | Width | Height | Has gable | Gable height | Openings area |
|---|---|---|---|---|---|
| Front | 40 | 10 | Yes | 5 | 48 |
| Back | 40 | 10 | No | 0 | 36 |
| Left | 25 | 10 | No | 0 | 12 |
| Right | 25 | 10 | Yes | 3 | 12 |
Dimensions above are in feet; switch units to convert automatically.
Results
Gross wall area0.00 ft²
Waste-adjusted area0.00 ft²
Estimated boxes needed0
Estimated panels needed0
Estimated material cost$0.00
Notes
- Panel count assumes consistent courses and minimal offcuts.
- Coverage per box varies by manufacturer and profile.
- Always verify with local codes and product instructions.
Coverage Reference (per box)
| Product type | Typical exposure | Coverage/box (ft²) | Coverage/box (m²) | Notes |
|---|---|---|---|---|
| Vinyl lap | 7–8 in | 200 | 18.58 | Common retail packaging |
| Fiber‑cement plank | 6–7 in | 100 | 9.29 | Often requires paint/prime |
| Engineered wood | 7–8 in | 120 | 11.15 | Brand‑dependent bundles |
| Cedar shakes | 5–7 in | 25 | 2.32 | Squares sold in bundles |
Values are typical references. Always confirm manufacturer coverage.
Waste Factor Guide by Elevation Complexity
| Complexity | Description | Typical waste % |
|---|---|---|
| Simple | Long runs, few penetrations | 5–7% |
| Moderate | Some corners, few gables | 8–12% |
| Complex | Multiple gables/dormers, many openings | 12–18% |
| Very complex | Irregular geometry, heavy detailing | 18–25% |
Use higher waste when patterns, angles, or short courses are frequent.
Exposure Conversions & Courses for a 10 ft Wall
| Exposure (in) | Exposure (ft) | Approx. courses needed |
|---|---|---|
| 4 | 0.333 | 30 |
| 6 | 0.500 | 20 |
| 7 | 0.583 | 18 |
| 8 | 0.667 | 15 |
| 10 | 0.833 | 12 |
Courses are rounded up. Starter strips and overlaps may change counts.