Free · Home and garden calculators 🏡

Shiplap Board Coverage and Material Budget

Estimate board counts for rectangular coverage, optional openings, spare-board allowance and quoted costs.

  • Formula & worked example
  • Private in your browser
  • No signup
Go to tool

Calculator inputs

Loading calculator…

How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

A 2 m by 2 m wall needs ten boards with usable coverage 2 m by 20 cm each. At 10 per board and installation at 2 per m², the material and installation budget is 108 before spare boards.

Board count = ceil(project area/usable board area); spare count = ceil(base count × (1+waste%)); total = boards × price + net area × installation rate.

Worked example

Enter these known values and leave the other values blank.

Length
2 m
Height
2 m
Length
200 cm
Width
20 cm
Shiplap board price
10 USD
Cost of installation
2 USD per m²
Project area
4 m²
Board size
4000 cm²
Shiplap
2.5 per m²
Number of shiplap boards
10
Shiplap cost
100 USD
Total installation cost
8 USD
Total expenses
108 USD

Assumptions and limitations

  • Board dimensions must represent usable coverage after overlap, not nominal lumber dimensions. The area estimate does not lay out rows, seam staggering or offcut reuse.
  • Waste rounds a spare-board allowance after rounding the net coverage count. Installation cost uses net project area, while material cost uses rounded boards.
  • Clear an unknown before solving backward. Currency controls represent the chosen denomination without exchange rates; prices must use the selected denominator units.
  • Whole package, board, roll or truss ceilings use exact decimal arithmetic. An amount just above a whole-number boundary needs the next whole unit; numeric display rounding does not lower the purchase count.

Common questions

What is included in this estimate?

Board dimensions must represent usable coverage after overlap, not nominal lumber dimensions. The area estimate does not lay out rows, seam staggering or offcut reuse.

References

Enforce the documented geometric domains and positive whole counts. Integer membership is checked with isInteger, so ordinary, tiny and large fractional counts are rejected even when tolerant floor equality would pass. Use exact decimal ceilings for whole material quantities; the captured mathjs ceiling snaps sufficiently near integers and can undercount immediately above a boundary.

Explore home and garden calculators 🏡 or browse all construction calculators.