Shiplap calculator
How many shiplap, tongue and groove or plank boards cover a wall, in linear feet and 8, 12 or 16 ft boards.
- Wall area covered
The exposed face is the width you see once boards are fitted together, which is less than the board's full width for shiplap and tongue and groove. Measure a board if you can. Includes 10% for cuts.
How to use it
Enter the wall's width and height, and the area of any windows or doors you'll board around. Then enter the board's exposed face width: the part that shows on the wall once the boards are fitted together. The calculator gives the linear feet of board and how many boards to buy with 10% extra for cuts.
The exposed face is what matters. Shiplap and tongue and groove boards overlap, so a board sold as a "1 × 6" (about 5½ in wide) shows less than that on the wall. Fit two offcuts together and measure, or check the product listing for its "coverage" or "face" width.
How it's calculated
- Area = width × height − openings.
- Linear feet = area ÷ (exposed face ÷ 12).
- Boards = linear feet × 1.1 ÷ board length, rounded up.
For an 8 ft high, 12 ft wide wall (96 sq ft):
| Exposed face | Linear feet | 12 ft boards with 10% | 16 ft boards with 10% |
|---|---|---|---|
| 3.5 in | 329 | 31 | 23 |
| 5.125 in | 225 | 21 | 16 |
| 5.5 in | 209 | 20 | 15 |
| 7.25 in | 159 | 15 | 11 |
Tips
- Stagger the joints between rows so they don't line up, and land them on studs if you're nailing.
- Use spacers (a nickel or a tile spacer) between plain boards for the classic shiplap gap.
- Let wood acclimate in the room for a few days before installing, so it doesn't shrink and open up gaps later.
- Painting the boards? Prime and paint the edges before they go up; it's hard to reach the gaps afterwards. The paint calculator works out how much you need.