Board and batten calculator.
Your wall, drawn to scale. Every batten located. Every board counted.
For n battens of width w on a wall of width L, the gap is (L − n × w) ÷ (n + 1) when the wall starts and ends with a space, or (L − n × w) ÷ (n − 1) when it starts and ends with a batten. A 121½-inch wall with five 2½-inch battens gives 18 3/16 inches.
02 / Your wall
TO SCALE| # | Left edge | Centre | Right edge |
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03 / What to cut
- Cut the spacer block to
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- Batten length
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- On an opening
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- Wall area
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- Board length in total
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- Boards to buy
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One spacer block, cut to the gap width, replaces every measurement on the wall. Mark the first batten, butt the block, mark the next.
How many boards, and where each cut falls.
| Board | Cuts | Offcut |
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Buying 8, 10 or 12 foot boards is not the same decision
The board length is the only choice here that changes what you spend without changing what you build: the same battens fall differently on an 8-foot board than on a 10-foot one, and the offcut column is the waste that decision costs you. The waste factor in the settings is a separate thing — it buys spare board against a bad cut, and is counted apart from the offcuts below so the two are never confused.
| Stock length | Boards to buy | Waste | Offcut total |
|---|
Lengths verified in stock on 2026-09-09: 8, 10, 12 feet. The 16-foot option is offered because it is common in pine, but it was not observed on the MDF references in that check.
The two layouts either side of your target
A whole number of battens rarely lands on a round spacing. These two layouts bracket what you asked for, so the rounding is your choice rather than ours.
| Layout | Gap | Gaps |
|---|
The arithmetic, on your own numbers
Everything on this page comes from one subtraction and one division. The battens take up n × w of the wall. What is left is the total gap. How many gaps that total is divided into depends on how the wall starts and finishes.
Worked example: a 121½-inch wall
Take a wall measuring 121½ inches between the inside corners, with five battens of primed MDF 1×3. The actual width of that board is 2½ inches, not 3 — see the table below.
- Battens take up 5 × 2½ = 12½ inches.
- What is left is 121½ − 12½ = 109 inches of gap in total.
- Starting and ending with a space, five battens make six gaps: 109 ÷ 6 = 18 3/16 inches each.
- Starting and ending with a batten, the same five make four gaps: 109 ÷ 4 = 27¼ inches each.
The two answers differ by nine inches on the same wall with the same materials. That is the edge condition, and it is a decision, not a default.
Where the first batten goes
With a space at each end, the left edge of the first batten sits one gap in — 18 3/16 inches in the example. With a batten at each end, it sits at zero. From there every batten advances by one gap plus one batten width, which is 20 11/16 inches in the first case. The table beside the drawing lists all of them cumulatively from the left edge, so nothing is measured off the previous mark.
A 1×3 is not three inches wide, and MDF is not softwood
A board sold as 1×3 measures 2½ inches. That much is widely repeated. What is not is that the thickness depends on the material: PS 20, the American Softwood Lumber Standard, gives ¾ inch for a dressed softwood board, while the primed MDF sold beside it on the same rack measures 11/16 inch — one sixteenth thinner. It matters at the one place a batten has to meet something: where it lands on an existing baseboard.
| Nominal | Material | Actual width | Actual thickness | Basis |
|---|---|---|---|---|
| 1×2 | Primed pine | 1-1/2″ | 3/4″ | Norme |
| 1×3 | Primed pine | 2-1/2″ | 3/4″ | Norme |
| 1×4 | Primed pine | 3-1/2″ | 3/4″ | Norme |
| 1×6 | Primed pine | 5-1/2″ | 3/4″ | Norme |
| 1×3 | Primed MDF | 2-1/2″ | 11/16″ | Relevé marché |
| 1×4 | Primed MDF | 3-1/2″ | 11/16″ | Relevé marché |
| 1×6 | Primed MDF | 5-1/2″ | 11/16″ | Relevé marché |
| 1×8 | Primed MDF | 7-1/4″ | 11/16″ | Relevé marché |
How far apart, really
10 to 12 inches is the range the top-ranked calculator for this term states, in its own words: “The most common spacing is 10 to 12 inches apart, but you can space the battens as close or far apart as you like.”. We class that as a convention and not a rule, because no building code and no product standard sets it. The constraint that does bite is physical: land the battens clear of outlets, switches and window returns.
How high the top rail sits, and what your baseboard does to it
The top rail is the horizontal board the battens die into, and its height is the decision the calculators skip. Around one third of the wall reads as a chair rail; around two thirds reads as tall panelling; the halfway point is the one proportion trim guides warn against, so the calculator says so when your figure lands there. At the bottom, battens usually stop on the existing baseboard rather than replacing it — enter its height and the batten length drops accordingly. If the baseboard leans out further than the batten is thick, a shoe molding closes the step instead of a rebuild.
When a batten lands on a window
Enter an opening and its distance from the left edge: any batten that overlaps it is drawn hatched, flagged in the position table and removed from the board count. It is not silently moved, because moving one batten breaks the even spacing the layout exists to produce. Shifting the run, splitting the wall either side of the opening or accepting one odd bay is a judgement — the drawing is there to let you make it.
Faux board and batten is not siding, and it is not wainscoting
Three things share these words. Interior faux board and batten — what this page calculates — is trim applied to a finished drywall accent wall: battens of primed MDF, pine or PVC, spaced however you like, with nothing structural about them. Board and batten siding, in vinyl or fibre cement, goes outside over sheathing, and its quantity comes from a fixed panel exposure rather than a spacing you choose, so none of the arithmetic here transfers. Wainscoting is a panelled treatment of the lower wall, where what gets divided is the field between stiles and rails, and it has its own calculator here. The second-ranked page for this term confuses the first with the third, and sends readers to a wainscoting calculator.
Before you cut
How to calculate for board and batten?
Subtract the width the battens take up from the wall width, then divide what is left by the number of gaps. Five battens make six gaps if the wall starts and ends with a space, four if it starts and ends with a batten. A grid divides the same way down the wall.
Is there a website that can calculate board and batten layouts?
Yes, this one. It returns every batten position measured from the left edge, your wall drawn to scale, the width to cut the spacer block, and the boards to buy at each stock length.
How far apart should boards be for board and batten?
10 to 12 inches is the usual range, including on the top-ranked calculator for this term. It is a convention, not a standard — no code sets it. Wider reads calmer, narrower reads traditional. What matters more: land the battens clear of outlets and window returns.
How do I calculate the spacing between boards?
Gap = (wall width − battens × batten width) ÷ gaps. On a 121 1/2 inch wall, five 2 1/2 inch battens and a space at each end: (121.5 − 12.5) ÷ 6 = 18 3/16 inches. Cut an offcut to that width and use it as a spacer block.
What is the board and batten spacing formula, going the other way?
Starting from a spacing rather than a count, it inverts: battens = (wall width + target gap) ÷ (batten width + target gap), rounded to a whole number, then the real gap comes back out of the first formula. Whole battens rarely land on a round gap, so this page shows both layouts either side of your target.
Does this work in centimetres or millimetres?
Yes. Switch to metric and the fields, the drawing and the cut list all follow, to the millimetre. You can also type 3m08 or 308 cm into an imperial field. Imperial output stays in sixteenths, because that is what a tape measure shows.
How many square feet of wall is this?
Wall width × height ÷ 144 gives square feet from inches, and the result panel shows it. It is the number for paint, and the wrong one for buying battens: boards sell by length, so the basket is decided by linear feet and by how the cuts fall on an 8, 10 or 12 foot board. Both are reported.
Is there a board and batten calculator app to install?
There is nothing to install. It runs in a phone browser on site, the arithmetic happens on your device rather than on a server, and the plan prints or exports as CSV so you can carry the cut list instead of the phone. No account, no email.
Is it free?
Yes, all of it — layout, drawing, positions, cut list, stock comparison, CSV and printable plan. Nothing behind a sign-up.
Does the wood change the numbers?
The width does, and it is not the one on the label. Primed pine and primed MDF sold as 1×3 both dress to 2 1/2 inches, so spacing is unchanged; their thickness differs, which decides whether a batten sits flush on your baseboard. Poplar and PVC are not in our own measurements, so we publish no sizes for them — read the product page and type the width in.
Can it do square board and batten, the grid pattern?
Yes. Switch the pattern to grid and set the number of horizontal rails: the wall is then divided the same way vertically, between top rail and baseboard, and the drawing shows the boxes you get. The rails enter the cut list at their own length, which is why a grid costs more board than it looks.
Does this work for vinyl board and batten siding outside?
No. Vinyl and fibre-cement siding comes as panels with a fixed exposure and an overlap, so quantity follows coverage per panel, not a spacing you choose. This page is interior faux board and batten, where the battens are trim on a finished wall.
What this does not do
- One flat wall at a time. Inside and outside corners, returns and chimney breasts are not modelled.
- Nothing is joined end to end: each piece is cut whole from one board, and no offcut is re-cut across boards. Within a board, the remainder does feed the next cut.
- The cutting plan is workable, not proven optimal — a first-fit decreasing pack. A kerf is charged between two cuts on the same board, not after the last one. Measure your own blade; the default is a placeholder, not a sourced value.
- No fixing schedule. How many brads, whether you find the studs or bond to the drywall with construction adhesive, and how much caulk closes the joints are trade decisions, not measurements, and we do not make them for you.
- No cost. We have not sourced a price per linear foot we are willing to publish with a date and a sample size, so this page does not show one. It will when we have.
- Fractions are displayed to the nearest 1/16 inch. The geometry keeps full precision underneath.
- Walls are assumed square, plumb and flat. They are not. Dry-fit the top rail first, and remember that furring strips over a wavy wall change the thickness you build up to, not the spacing.