Calculator Inputs
Enter wall dimensions, board settings, waste rate, and cost values. The result appears above this form after submission.
Example Data Table
| Total Wall Length | Wall Height | Gable Area | Openings | Board Length | Reveal | Waste | Boards Needed | Bundles | Total Cost |
|---|---|---|---|---|---|---|---|---|---|
| 144 ft | 10 ft | 54 sq ft | 210 sq ft | 12 ft | 7 in | 10% | 196 | 14 | $4,012.40 |
This example shows a typical lap siding takeoff using four main walls, one front gable, a standard reveal, and an added waste allowance.
Formula Used
(Wall 1 + Wall 2 + Wall 3 + Wall 4) × Wall Height + Extra Wall Area + (Gable Width × Gable Height ÷ 2)
Gross Wall Area − Openings Area
Board Length × (Exposed Height ÷ 12)
Ceiling[(Net Coverage Area ÷ Coverage per Board) × (1 + Waste Percentage)]
Boards Needed × Fasteners per Board
Siding Material Cost + Trim Cost + Labor Allowance
How to Use This Calculator
- Enter each wall length and the common wall height.
- Add any extra wall area not covered by the four main lengths.
- Enter gable width and height if your elevation includes one.
- Subtract doors, windows, and other uncovered opening areas.
- Enter board length and visible installed reveal height.
- Set waste percentage for cuts, breakage, and layout losses.
- Add board cost, trim cost, and labor allowance values.
- Click calculate to see boards, bundles, fasteners, waste, and cost totals.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates gross wall area, net siding coverage area, boards required, bundle count, fasteners, waste allowance, trim cost, labor allowance, and total projected budget.
2) Should I enter nominal board width?
No. Enter the visible exposed height, also called reveal. Installed coverage depends on the portion left visible after overlap, not the full board width.
3) Why should I include waste percentage?
Waste covers cuts, breakage, layout trimming, starter rows, end matching, and jobsite handling. Complex elevations usually need a higher waste allowance than simple rectangles.
4) Can I use this for gable walls?
Yes. Enter the gable width and height. The calculator converts that triangular section into area and adds it to the main wall surface.
5) Does it subtract doors and windows?
Yes. Add the total area of openings that will not receive siding. This helps avoid overstating board count and total material cost.
6) Are trim and labor included?
Yes. You can add trim length with a unit price and apply a labor allowance per square foot for a broader job estimate.
7) Is the board count exact?
It is an estimating tool. Actual field conditions, stagger pattern, corner detailing, window wrapping, and manufacturer installation rules can change final ordering quantities.
8) What unit system does this page use?
Wall and board lengths use feet, reveal uses inches, and area uses square feet. Keep all entries in those units for accurate results.