How many shiplap boards do I need for a wall?

Work out the rows (wall height ÷ the exposed face, rounded up), cut each row from boards, and add waste. A 12 × 8 ft wall in 1 × 6 shiplap is 21 rows of 12 ft; with 8 ft boards each row is a whole board plus a 4 ft piece, and the 4 ft pieces pair up on shared boards, which is 32 boards before waste and 36 with 10%. The calculator does this for any wall size, direction and board length.

What is the exposed face of shiplap, and why does it matter?

It is the width one board covers once it is lapped into its neighbour. It is always less than the board's width: a UFP-Edge 1 × 6 shiplap is 5 3/8 in wide with a 4 5/8 in exposed face, and a UFP-Edge Timeless 1 × 8 nickel-gap pine board has a 6 7/16 in face. Using the nominal 5 1/2 in or 7 1/4 in would put you short by a row or more, so use the face on the label. Pick Custom for any other board; the numbers here are typical, not universal.

Should I use 8, 10, 12 or 16 ft boards?

Choose the length that leaves the least cutting and the fewest joints. The example 12 ft wall takes 36 boards of 8 ft but 24 of 12 ft, because each row is then one whole board. Longer boards cost more per foot and are harder to carry and hold overhead, so compare the price per linear ft of what the store has.

How do I allow for doors and windows?

Add each as an opening, width then height. The calculator takes its area off the wall and shortens every row in proportion, because shiplap rows run through the sides of an opening rather than stopping. A 14 × 9 ft wall with a 3 × 6.7 ft door and a 3 × 4 ft window needs 93.9 sq ft of boards, 37 boards of 8 ft with 15% waste. The proportional method is an estimate: cutting around an opening wastes more than a plain wall, which is why 15% is offered.

How much waste should I allow?

About 10% for a plain wall and 15% for a wall with openings or a ceiling is common in installation guides and calculators; they are estimates, not manufacturer figures. The count is already packed to whole boards with offcuts reused, so the allowance covers bowed or damaged boards and mistakes. With no waste the example wall is 32 boards instead of 36.

How do I work out a ceiling?

Enter the room length and width as the wall width and height, and add the light fittings as openings if they are large. Horizontal runs along the length. Boards overhead are hard to fit and cut, so choose the 15% waste option. A 14 × 12 ft ceiling in 1 × 8 nickel-gap boards of 12 ft is 23 rows and 32 boards with 15% waste.

Horizontal or vertical: which takes more?

Vertical boards run floor to ceiling, so the count is the wall width ÷ the exposed face, with each board the wall height. A 10 × 8 ft wall in 1 × 8 nickel-gap boards of 10 ft is 19 boards across, each cut from a 10 ft board, 21 boards with 10% waste. The area is the same, so the totals are close; vertical walls cut with less joining when the boards are as long as the wall is tall.

How many nails do I need?

This calculator does not count nails. We could not find a manufacturer or code source that gives a nail count per board or per stud, so any number would be a guess. Follow the installation sheet of the boards you buy for the nail type, length and placement. In general, fasten into studs where you can, and use adhesive on drywall as the sheet allows.

Do I need to stagger the joints?

Yes, for a good finish: end joints that line up in neighbouring rows are easy to see, so move each joint at least a stud space from the one below, and land every joint on a stud so both ends are nailed. The cut list assumes a joint wherever a row is longer than your boards; the number of boards is the same wherever you put them.

How do I use the cut list?

It shows how the pieces are cut from the boards before waste. For the example wall: 21 × 96 in; 10 × 48 in + 48 in; 1 × 48 in. Cut the long piece of a row first, keep the remainder, and fit it into the next row's joint if it is long enough.

Shiplap Calculator: Boards for an Accent Wall or Ceiling

A 12 ft wide, 8 ft tall wall covered with horizontal 1 × 6 shiplap (a typical 4 5/8 in exposed face) needs 36 boards of 8 ft with 10% waste. The wall takes 21 rows, each 12 ft long, so each row is an 8 ft board plus a 4 ft piece, and the offcuts are shared between rows. The 36 boards are 288 linear ft and about 111 sq ft of covering, for 96 sq ft of wall. The exposed face is the width a board covers once lapped, not its width; it is an editable typical figure, so check the label of your boards.

Figures based on the sources listed belowUpdated 2026-10-17How we calculate

Wall width (or ceiling length)

Wall height (or ceiling width)

Waste (estimate)

Plain wall (10%, estimate)Openings, ceiling or diagonal cuts (15%, estimate)Exact (0%)Custom

Board directionHorizontal rows are stacked up the wall. Vertical boards stand side by side. On a ceiling, enter the length and width and the boards run along the length when horizontal.

BoardThe exposed face is what a board covers once it is lapped, less than its width. Faces differ by maker and profile, so read the label or measure a sample and use Custom if yours is different.

Board lengthThe length you will buy. Rows longer than the board are joined, and offcuts are reused to start other rows.

Price per board (optional)

Buy 36 boards

96 sq ft + 10% waste = 105.60 sq ft

Rows of boards: 21 rows, each 12 ft long before openings
Area to cover (after openings): 96 sq ft
Boards (8 ft): 36 boards, some rows are longer than a board and are joined; stagger the joints
Cut list (first-fit, inches): 21 × 96 in; 10 × 48 in + 48 in; 1 × 48 in (before waste)
Area purchased (exposed face): 111 sq ft
Linear feet purchased: 288 ft

How this number is calculated

96 sq ft + 10% waste = 105.60 sq ft ÷ 2.93 sq ft per board = 36 boards

Shopping list

1 × 6 shiplap boards
Nickel gap shiplap
18-gauge brad nailer
Laser level
Stud finder
Paintable caulk

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Rows or boards across by wall height

Horizontal rows for a wall of that height (or vertical boards across a wall of that width), worked by this calculator for the two typical exposed faces.
Height or width	1 × 6 shiplap (4 5/8 in face)	1 × 8 nickel gap (6 7/16 in face)
8 ft	21	15
9 ft	24	17
10 ft	26	19
12 ft	32	23

Boards of 8 ft for horizontal 1 × 6 shiplap

Plain walls with no openings, 4 5/8 in exposed face, 10% waste, offcuts reused, worked by this calculator. Walls with openings need fewer boards before waste; ceilings should use 15%.
Wall width	8 ft tall	9 ft tall
8 ft	24	27
10 ft	30	33
12 ft	36	40
14 ft	47	53
16 ft	47	53

Methodology & assumptions

The wall width and height are in feet (for a ceiling, its length and width), and the openings you add come off the area. Horizontal boards: rows = wall height ÷ exposed face, rounded up, each row as long as the wall is wide. Vertical boards: boards across = wall width ÷ exposed face, rounded up, each as long as the wall is tall. The exposed face is the width a board covers once the lap is closed, not the width of the board: for UFP-Edge 1 × 6 shiplap the board is 5 3/8 in wide and the exposed face 4 5/8 in, and for UFP-Edge Timeless 1 × 8 nickel-gap pine the exposed face is 6 7/16 in. Those are the typical figures we offer, taken from product listings; other makers and profiles differ, so measure your boards and use the custom face if they do. Openings shorten the rows rather than remove them (a window cuts a piece out of the rows it crosses), so every row is shortened in proportion, by net area ÷ gross area. A row longer than your board is made from whole boards plus a remainder, which means a joint, so stagger the joints from row to row and keep them on studs. All the pieces are then packed onto boards of your length, longest first, each on the first board with room (first-fit decreasing, the same cut-list helper as the board and batten and crown molding calculators), so a short remainder is taken from an offcut instead of a new board. Saw kerf is not modeled. The waste you choose (an estimate, 10% for a plain wall, 15% with openings or a ceiling) is added to that board count and rounded up. Area purchased is boards × board length × exposed face, and linear feet purchased is boards × board length. Nails and adhesive are not counted: no source for a nail count per stud was found, so follow the installation sheet of the boards you buy. The metric toggle shows lengths in m and the custom face in cm.

UFP-Edge 1 × 6 shiplap product document (Lowe’s product documents): 5.375 in wide, 0.625 in thick, 4.625 in exposed face
UFP-Edge 1 in x 8 in x 8 ft Timeless Granite Gray Smooth Nickel Gap Pine Shiplap Board, 4-pack (Home Depot Canada listing): exposed face 6-7/16 in, 4.29 sq ft a board
ARAUCO 9/16 in x 5-1/4 in x 8 ft Primed Pine Nickel Gap Ship Lap Board, 6 per box (Home Depot listing): the listing gives the board width but no exposed face, which is why the face is editable
Waste: 10% for a plain wall, 15% for a wall with openings or odd shapes and 12 to 15% for a ceiling are common figures in shiplap calculator guides. An estimate, not a manufacturer figure; the cut list is already packed to whole boards
Stock lengths: boards are commonly sold in 8, 10, 12 and 16 ft lengths (a typical range; stock varies by store and species, so check what is on the shelf)

How to estimate shiplap

Measure the wall or ceiling. Measure the width and height of the wall between the corners, or the length and width of the ceiling, and the doors and windows to leave out.
Find the exposed face. Read the exposed face (or coverage) on the label of your boards, or measure two boards fitted together. It is less than the board width.
Count the rows. Divide the wall height by the exposed face and round up for horizontal rows. For vertical boards, divide the wall width.
Cut from your board length. Cut each row from whole boards plus a remainder, reusing offcuts to start other rows, and stagger the joints on studs.
Add waste and buy. Add 10% for a plain wall, 15% for openings or a ceiling, and round up to whole boards.

Worked examples

Project	Result
12 × 8 ft wall, horizontal 1 × 6 shiplap, 8 ft boards, 10% waste	36 boards (21 rows, 288 linear ft, about 111 sq ft)
14 × 9 ft wall with a 3 × 6.7 ft door and a 3 × 4 ft window, 1 × 6 shiplap, 8 ft boards, 15% waste	37 boards (93.9 sq ft, 24 rows)
10 × 8 ft wall, vertical 1 × 8 nickel-gap boards, 10 ft boards, 10% waste	21 boards of 10 ft (19 across)
14 × 12 ft ceiling, 1 × 8 nickel-gap boards, 12 ft boards, 15% waste	32 boards of 12 ft (23 rows)

Frequently asked questions

How many shiplap boards do I need for a wall?: Work out the rows (wall height ÷ the exposed face, rounded up), cut each row from boards, and add waste. A 12 × 8 ft wall in 1 × 6 shiplap is 21 rows of 12 ft; with 8 ft boards each row is a whole board plus a 4 ft piece, and the 4 ft pieces pair up on shared boards, which is 32 boards before waste and 36 with 10%. The calculator does this for any wall size, direction and board length.
What is the exposed face of shiplap, and why does it matter?: It is the width one board covers once it is lapped into its neighbour. It is always less than the board's width: a UFP-Edge 1 × 6 shiplap is 5 3/8 in wide with a 4 5/8 in exposed face, and a UFP-Edge Timeless 1 × 8 nickel-gap pine board has a 6 7/16 in face. Using the nominal 5 1/2 in or 7 1/4 in would put you short by a row or more, so use the face on the label. Pick Custom for any other board; the numbers here are typical, not universal.
Should I use 8, 10, 12 or 16 ft boards?: Choose the length that leaves the least cutting and the fewest joints. The example 12 ft wall takes 36 boards of 8 ft but 24 of 12 ft, because each row is then one whole board. Longer boards cost more per foot and are harder to carry and hold overhead, so compare the price per linear ft of what the store has.
How do I allow for doors and windows?: Add each as an opening, width then height. The calculator takes its area off the wall and shortens every row in proportion, because shiplap rows run through the sides of an opening rather than stopping. A 14 × 9 ft wall with a 3 × 6.7 ft door and a 3 × 4 ft window needs 93.9 sq ft of boards, 37 boards of 8 ft with 15% waste. The proportional method is an estimate: cutting around an opening wastes more than a plain wall, which is why 15% is offered.
How much waste should I allow?: About 10% for a plain wall and 15% for a wall with openings or a ceiling is common in installation guides and calculators; they are estimates, not manufacturer figures. The count is already packed to whole boards with offcuts reused, so the allowance covers bowed or damaged boards and mistakes. With no waste the example wall is 32 boards instead of 36.
How do I work out a ceiling?: Enter the room length and width as the wall width and height, and add the light fittings as openings if they are large. Horizontal runs along the length. Boards overhead are hard to fit and cut, so choose the 15% waste option. A 14 × 12 ft ceiling in 1 × 8 nickel-gap boards of 12 ft is 23 rows and 32 boards with 15% waste.
Horizontal or vertical: which takes more?: Vertical boards run floor to ceiling, so the count is the wall width ÷ the exposed face, with each board the wall height. A 10 × 8 ft wall in 1 × 8 nickel-gap boards of 10 ft is 19 boards across, each cut from a 10 ft board, 21 boards with 10% waste. The area is the same, so the totals are close; vertical walls cut with less joining when the boards are as long as the wall is tall.
How many nails do I need?: This calculator does not count nails. We could not find a manufacturer or code source that gives a nail count per board or per stud, so any number would be a guess. Follow the installation sheet of the boards you buy for the nail type, length and placement. In general, fasten into studs where you can, and use adhesive on drywall as the sheet allows.
Do I need to stagger the joints?: Yes, for a good finish: end joints that line up in neighbouring rows are easy to see, so move each joint at least a stud space from the one below, and land every joint on a stud so both ends are nailed. The cut list assumes a joint wherever a row is longer than your boards; the number of boards is the same wherever you put them.
How do I use the cut list?: It shows how the pieces are cut from the boards before waste. For the example wall: 21 × 96 in; 10 × 48 in + 48 in; 1 × 48 in. Cut the long piece of a row first, keep the remainder, and fit it into the next row's joint if it is long enough.

Handy tools

Feet and Inches Calculator: Add up a wall measured in feet, inches and fractions, and get decimal feet for the wall width and height.