A simple layout with two fixed ends
This calculator distributes vertical decorative battens over a rectangular surface. There is one full batten at each end and an equal clear gap between every pair. Enter the width, the height of the vertical pieces, the actual visible face width and the number of empty bays you want. Six bays require seven battens.
The two spacing measurements
Clear gap = (wall width − (bays + 1) × batten width) ÷ bays. Centre-to-centre spacing = clear gap + batten width. The position of each left edge is its zero-based index multiplied by the centre spacing. The last batten’s right edge matches the wall width. The centre position is the left edge plus half the face width.
Worked example
For a 300 cm wide surface, 4 cm battens and six bays, the seven battens occupy 28 cm. The remaining 272 cm is divided into six clear gaps of 45.33 cm. The centre spacing is 49.33 cm. The final batten starts at 296 cm and ends at 300 cm. At 120 cm tall, the seven vertical pieces total 8.4 m.
What the material total excludes
The total is the sum of the finished vertical pieces. It excludes rails, backing boards, stock-cutting waste, fixings and spare material. This tool does not model windows or doors. It is not an exterior siding specification, a structural design or a fixing schedule. Use the actual face width of the product, and check the real surface before transferring the marks.
Use the marking table
The table gives positions measured from the left boundary. Use those common-origin measurements rather than adding rounded gaps one after another. Export the SVG or text summary to keep the layout. Recalculate after changes so that your downloaded plan corresponds to the dimensions on screen.
Common questions
What is a bay?
A bay is the open space between two battens. This tool uses one more batten than the number of bays because both ends have a batten.
Can I omit the end battens?
This model always includes both end battens. A design without them needs a different calculation.
Does it calculate rails?
No. The reported length includes only the vertical pieces at the height you enter.