Walls & Ceilings
Plan horizontal shiplap or similar lap-board wall coverage from installed face width rather than nominal board width. The calculator turns wall height into courses, then converts the repeated wall run into stock pieces while leaving fastening, backing and moisture details outside the arithmetic.
Change the defaults to match your project and the product you plan to buy.
Project result
Review board courses, linear footage, allowance and whole stock pieces.
At a glance
Planning estimate only. Verify product coverage, package size, supplier specifications and project requirements before purchasing.
Budget scenario
Use a current supplier subtotal or reuse a priced calculator result, then add optional delivery, tax and contingency. Home Measure Lab does not fetch or guess live prices.
Enter a current supplier subtotal or reuse a priced calculator result.
Budget values are local planning inputs, not live quotes. Verify tax treatment, delivery, labor and supplier pricing before purchasing.
Choose the right tool
You are planning horizontal shiplap/lap boards from installed face width and stock length.
Use Wall Paneling for sheet panels or Ceiling Plank for ceiling-oriented linear planks.
Methodology
wall height ÷ installed face width, rounded up
Uses exposed/installed coverage, not nominal width.
courses × wall width
Represents one horizontal run per course.
base linear run × (1 + allowance)
Keeps cutting and selection reserve visible.
planning target ÷ stock length, rounded up
Converts to the selected stock length.
Measure each continuous wall field and use the installed face width shown by the selected shiplap profile. Wall height controls the number of courses while wall width controls the linear run in each course. Treat doors, windows, short returns and vertical orientation as separate layout zones if they materially change usable offcuts or board direction.
Confirm actual face coverage, available stock lengths and grade before using the purchase result. Boards with lap, tongue or reveal details may cover less than their nominal width. The calculator uses a simple linear-foot takeoff and does not optimize staggered joints, so keep a reasonable explicit allowance and review stock-length choices against the real wall layout.
Reference
| Layer | Quantity basis | Keep external |
|---|---|---|
| Courses | wall height ÷ installed face width | Profile and orientation choice. |
| Linear run | courses × wall width | Joint staggering/layout. |
| Allowance | explicit cut/selection reserve | Board grade and usable offcuts. |
| Purchase | whole boards by stock length | Fastening/backing and moisture details. |
Questions
Overlap, tongue engagement or reveal geometry can reduce actual coverage, so the installed face width is the quantity-driving dimension.
No. It provides a linear stock takeoff; seam staggering and cut optimization should be reviewed against the wall layout and available board lengths.
The current formula models horizontal courses. For vertical installation, use a separate linear layout or calculate each wall using the orientation-specific geometry.
Planning guides
Walls & Ceilings
Use installed shiplap face width rather than nominal board width to determine courses and avoid overstating coverage from lap or tongue profiles.
Read guide →Walls & Ceilings
Convert shiplap course footage into stock boards while keeping seam staggering, cut allowance and usable offcuts separate from measured wall geometry.
Read guide →Estimate sheet or panel count from measured wall dimensions, major openings, panel dimensions, cutting allowance and optional panel price.
Open calculator → Walls & CeilingsEstimate gross and net wall area from room dimensions, height, doors and windows in US or Metric units.
Open calculator → InteriorEstimate baseboard or trim linear feet and number of stock pieces for a rectangular room.
Open calculator →