Shiplap Calculator
Plan a shiplap accent wall, room or ceiling. Enter your wall size and any doors or windows, pick the board size, length, direction and waste allowance, and get the square footage, linear feet, number of boards to buy, rows per wall, nails, paint and an estimated material cost — with board-size and board-length comparisons, a chart and a downloadable PDF.
| Board size | Linear ft + waste | Boards | Board cost |
|---|---|---|---|
| Enter your wall size to compare | |||
| Board length | Boards | Pieces per row | Board cost |
|---|---|---|---|
| Enter your wall size to compare | |||
How to use the shiplap calculator
Four quick steps turn your wall size into linear feet, boards to buy, rows, nails, paint and cost — with by-board-size and by-board-length tables, a chart and a downloadable report.
Measure the wall
Enter the width and height in feet, how many matching walls, and any doors, windows or other openings.
Pick the boards
Choose 1×4, 1×6, 1×8 or 1×10 shiplap and a board length of 8, 10, 12 or 16 ft.
Set direction & waste
Pick horizontal, vertical or diagonal, a 5–20% waste factor, and your board, paint and nail prices.
Read results & save a PDF
Get boards, linear feet, rows, last-row width, nails, paint and cost — then download a report.
How shiplap is calculated
Shiplap coverage depends on each board’s face exposure — the visible width after the boards overlap — not its nominal size. Here is the exact math the calculator runs.
Worked example — 12 × 8 ft accent wall, 1×6 shiplap, 8 ft boards, horizontal, 10% waste
Area: 12 × 8 = 96 sq ft · Linear ft: 96 × 12 ÷ 5.125 ≈ 225 ft · With waste: 225 × 1.10 ≈ 247 ft
Boards: 247 ÷ 8 → 31 boards (248 ft) · Rows: 96" ÷ 5.125" → 19 rows, last row 3-3/4" · 2 pieces per row
Nails: ≈ 380 (1 box) · Paint: 96 × 2 ÷ 350 ≈ 0.55 → 3/4 gal · Cost: $434 boards + $34 paint + $12 nails ≈ $480
≈ 31 boards of 8 ft 1×6 shiplap — about $480, or $5.00 per sq ft, including paint and nails.
Shiplap reference charts
Handy lookups for how board size and board length change what you buy for a 12 × 8 ft wall, plus how direction and waste affect it.
| Board size | Linear ft + waste | Boards | Board cost |
|---|---|---|---|
| 1×4 · 3-1/8″ face | 406 ft | 51 | $714 |
| 1×6 · 5-1/8″ face | 247 ft | 31 | $434 |
| 1×8 · 6-7/8″ face | 184 ft | 24 | $336 |
| 1×10 · 8-7/8″ face | 143 ft | 18 | $252 |
Wider boards cover faster with fewer rows; narrower boards give a tighter, busier pattern.
| Board length | Boards | Pieces per row | Board cost |
|---|---|---|---|
| 8 ft | 31 | 2 | $434 |
| 10 ft | 25 | 2 | $438 |
| 12 ft | 21 | 1 | $441 |
| 16 ft | 16 | 1 | $448 |
A board as long as the wall means one piece per row and no seams. Cost is for full boards bought.
| Direction | Waste | Boards | Rows · last row |
|---|---|---|---|
| Horizontal | 10% | 31 | 19 · 3-3/4″ |
| Vertical | 10% | 31 | 29 · 1/2″ |
| Diagonal | 15% | 33 | 19 · 3-3/4″ |
Vertical boards need blocking or furring strips every 24″. A very thin last row is a sign to rip the first and last boards evenly.
What the shiplap calculator gives you
Wall size and a few board choices give you a full shopping list and layout plan.
Shiplap at a glance
Who uses a shiplap calculator
From a single accent wall to a whole room, the same calculator builds the shopping list.
Adding a farmhouse accent wall and wants to know how many boards to grab and what it will cost.
- Enter one wall
- Pick 1×6 boards
- Use 10% waste
Covering every wall in a bedroom or mudroom and needs to subtract doors and windows.
- Add doors and windows
- Pick longer boards
- Budget paint coats
Pricing shiplap installs and wants board counts, rows and material cost per square foot.
- Compare board sizes
- Check the last row
- Share the PDF
Tips for a clean shiplap install
Good shiplap is all about straight rows and tidy edges — these habits get you there.
Shiplap calculator FAQ
Quick answers about how much shiplap you need, face exposure, waste, board length, direction and cost.
A 12 × 8 ft wall is 96 sq ft. With 1×6 shiplap (5-1/8 inch face), that is about 225 linear feet, or about 247 feet with 10% waste.
In 8 ft lengths you need 31 boards. In 12 ft lengths you need 21 boards, with one piece per row and no seams.
Multiply the net wall area in square feet by 12, then divide by the board’s face exposure in inches. Add your waste factor and divide by the board length to get the number of boards.
For 96 sq ft of 1×6: 96 × 12 ÷ 5.125 ≈ 225 linear feet, plus 10% ≈ 247 feet, or 31 boards of 8 ft.
Shiplap overlaps, so coverage is based on the face exposure, not the nominal size. A 1×6 covers about 5-1/8 inches, a 1×4 about 3-1/8 inches, a 1×8 about 6-7/8 inches and a 1×10 about 8-7/8 inches.
Exposure varies by mill, so measure the visible width of one board before you buy.
Add about 10% for straight horizontal or vertical layouts to cover end cuts, outlets, knots and mistakes.
Use 15% to 20% for diagonal patterns or walls with many openings. On a 12 × 8 ft wall, a diagonal layout at 15% needs 33 boards instead of 31.
Yes. The calculator subtracts about 21 sq ft for a standard door and 15 sq ft for a standard window, plus any other openings you enter.
A room with 48 ft of 8 ft walls, 1 door and 2 windows is 384 − 51 = 333 sq ft, which needs about 108 boards of 8 ft 1×6 shiplap.
Longer boards mean fewer seams. Pick a length close to your wall width, or a little over, so each row needs fewer pieces.
On a 12 ft wall, 8 ft boards need 2 pieces per row, while 12 ft or 16 ft boards cover each row in one piece.
Horizontal shiplap makes a room feel wider and nails straight into studs every 16 inches. Vertical shiplap makes ceilings feel taller but needs horizontal blocking or furring strips every 24 inches.
Diagonal patterns are the most dramatic and the most wasteful, so plan 15% waste or more.
Primed MDF shiplap often runs about $0.75 to $1.50 per linear foot, primed pine about $1.25 to $2.50, and cedar or hardwood $3 or more.
At $1.75 per linear foot, a 12 × 8 ft wall costs about $434 in boards — about $480 with 2 coats of paint and a box of nails, or $5.00 per sq ft.
Planning aid only — confirm with your supplier. This calculator works in US units (feet, inches) and bases coverage on each board’s face exposure, which varies by mill — measure one board before you buy. Add about 10% waste for straight runs and 15% or more for diagonal layouts. Prices are examples only; check your local store, and follow the manufacturer’s installation instructions.