Inputs
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Results
Enter inputs and click Calculate.
Pack-size optimizer
Comma separated integers (e.g., 4,6,8,10,12).
Example data table
| Profile | Face (mm) | Overlap (mm) | Gap (mm) | Effective cover (mm) |
|---|---|---|---|---|
| Shiplap 140 | 140 | 20 | 0 | 120 |
| T&G 120 | 120 | 0 | 0 | 120 |
| Open-joint 90 + 10 gap | 90 | 0 | 10 | 100 |
| Bevel 150 | 150 | 25 | 0 | 125 |
Effective cover = face − overlap + gap.
Formula used
The calculator uses two complementary methods and selects a conservative value.
-
Course/column method (layout aware):
- Effective cover:
cover = face − overlap + gap(must be > 0). - Horizontal:
courses = ceil(height / cover),boardsPerCourse = ceil(width / boardLen),boards = courses × boardsPerCourse. - Vertical:
columns = ceil(width / cover),boardsPerColumn = ceil(height / boardLen),boards = columns × boardsPerColumn. - Openings reduce boards by area-equivalent:
openingBoards ≈ openingArea / (cover × boardLen).
- Effective cover:
-
Area method (fast estimate):
- Net area:
wallArea − Σ openings. - Board cover area:
cover × boardLen. - Boards:
ceil(netArea / boardCoverArea).
- Net area:
The final count per wall is the maximum of the two methods (ensuring you aren’t short) and then adjusted by waste.
How to use this calculator
- Select unit system, orientation, and enter board face, length, overlap or gap.
- Add each wall: width and height. Click its “Openings” to add windows/doors.
- Set waste allowance and optional pack size or unit cost.
- Press Calculate. Review wall-by-wall boards and overall totals.
- Use the optimizer to pick pack combinations with minimal overage.
- Copy a shareable URL to save or send your configuration.
- Export to CSV or PDF for estimating, procurement, or site crews.
FAQs
Yes. Overlap reduces vertical cover per course. Effective cover = face − overlap (horizontal). For vertical open-joint, effective horizontal cover = face + gap.
Openings subtract area from walls. We also adjust using an area-equivalent board count to avoid over-estimating around edges and trims.
Horizontal uses courses and boards per course. Vertical uses columns and boards per column. Gap is typically considered horizontally when vertical open-joint is selected.
Boards per course or column reduce to one piece when board length fully spans the required dimension.
Use the waste percentage to include ancillaries. For detailed takeoffs, add linear trim to walls and convert to boards by
trimLength / boardLen.Follow the manufacturer’s installation guide for acclimation and expansion gaps. Increase waste allowance for higher movement species or site-cut intensive projects.
We compute both and choose the higher (safer) result after opening adjustments. This reduces the risk of being short on site.
Pack count is simply boards divided by boards per pack, rounded up. Check real pack sizes and keep extra for damages.
Yes. Change the unit system at the top. Labels and conversions update, and all calculations convert internally.
The layout method assumes practical staggering by using board length against wall span. It intentionally rounds up to cover waste from staggering.
No. This tool targets cladding boards. For rainscreen battens or substructure, use dedicated calculators or add a separate line in your estimate.
Always verify against supplier guidance and drawings before ordering.