What this calculator does
Battens are counted from the wall width divided by the spacing, plus one for the closing end. A 6 metre wall at 400 mm centres takes 16 battens, leaving a 355 mm gap between them.
The spacing is an aesthetic decision with a real material cost. Tightening from 600 to 300 mm centres takes the count from 11 to 21 and the total batten length from 26.4 to 50.4 metres, nearly double. Wider spacing reads as more modern and narrower as more traditional, and the price difference is not trivial.
The formula
Battens are the wall width divided by the spacing, rounded down, plus one, since a run needs a batten at both ends. The gap is the spacing less the batten width. Base boards are the wall width divided by the board width, rounded up, and the batten length total multiplies the count by the wall height.
| Term | Meaning |
|---|---|
| Batten | The narrow vertical strip covering the joint between base boards. |
| Base board | The wide board beneath, which the battens are fixed over. |
| Centre to centre | Batten spacing measured from the middle of one to the middle of the next. |
| Reveal | The visible gap between battens, which is the spacing less the batten width. |
The inputs explained
| Field | What to enter |
|---|---|
| Wall width (m) | Wall width in metres. |
| Wall height (m) | Wall height. |
| Batten spacing (centre to centre) (mm) | Batten spacing, centre to centre. 300 to 600 mm covers most looks. |
| Batten width (mm) | Batten width in millimetres. |
| Base board width (mm) | Base board width, for the board count beneath. |
When to use it
Cladding a wall
Battens and boards are ordered separately and each needs its own count.
Choosing a spacing
The look and the cost both follow from the spacing, so seeing both together helps.
Estimating an interior feature wall
The same arithmetic applies to decorative internal battening, which is a common feature treatment.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How does spacing change the batten count?
The same wall at a range of batten spacings.
| Batten spacing | Battens needed | Gap between battens | Total batten length |
|---|---|---|---|
| 300 mm | 21 | 255.0 mm | 50.4 m |
| 400 mm | 16 | 355.0 mm | 38.4 m |
| 600 mm | 11 | 555.0 mm | 26.4 m |
Questions
What batten spacing looks best?
It depends on the effect. Around 300 mm reads as traditional and busy, 400 to 500 mm as balanced, and 600 mm or wider as modern and restrained. Scale matters: wide spacing on a small wall can look sparse, and tight spacing on a large one looks fussy.
Do the battens cover the board joints?
That is the traditional purpose. Board and batten evolved to cover the gaps between wide boards as they shrank, which is why the batten sits over the joint. Modern decorative battening is often applied over sheet material where there are no joints to cover.
Why one more batten than the spacing suggests?
Because a run needs a batten at both ends, so n bays between battens means n plus one battens. The same logic governs fence posts and wall studs, and forgetting it leaves you one short at the last wall.
Does this include the base boards behind?
It counts them, assuming the boards butt edge to edge across the wall width. If the boards overlap or have a shiplap profile, the effective cover per board is less than its full width and the count will be higher than reported.
For fence boards instead, see the fence calculator. For the framing behind, see the wall stud calculator.