Timber in metres: board feet, linear metres and m³
7 min read · Updated 2026-10-12 · BuildCalc
Timber is the one material where the metric and imperial worlds genuinely disagree about what to call a quantity. American suppliers sell by the board foot and price by the linear foot; European suppliers sell by the cubic metre and price by the metre of length. Neither is wrong, but mixing the two on the same job is how people end up with a stack that is twice what they need.
Board foot, linear metre and cubic metre are three different things
A board foot is a volume: one square foot of lumber one inch thick, which works out at 12 × 12 × 12 inches. A linear metre is a length. A cubic metre is a volume. Converting between them requires a width and a thickness, because length alone cannot tell you how much timber you have.
The useful rule: one board foot equals about 0.00236 cubic metres. A single 5 × 10 cm timber 2.4 metres long is 0.05 × 0.10 × 2.4 = 0.012 cubic metres, or roughly 5 board feet. Once you have the section size, every conversion follows.
Framing a wall in metric
Stud spacing is the same almost everywhere — 40 cm or 60 cm centres — because it comes from the width of sheet material and the size of a sheet, not from any national standard. Count the spaces, multiply by the spacing, and you get the total horizontal run of studs; add one stud if the wall height does not divide evenly into the spacing.
For a wall 4.8 metres wide with studs at 40 cm centres: 4.8 ÷ 0.4 = 12 spaces, so 13 studs. At 2.4 metres tall those are 13 × 2.4 = 31.2 linear metres of 100 × 50 timber, before headers, noggings or the extra studs either side of an opening.
Decking, boards and the waste that differs by material
Deck boards are ordered by linear metre and by board width, and the number you need is the deck area divided by the board's coverage, plus cuts. Allow five to ten per cent for a simple rectangular deck and considerably more when boards run at an angle, because every intersection throws off an offcut.
Solid timber framing behaves differently. It is dimensioned in nominal sizes that are larger than the finished size — a nominal 100 × 50 is planed down to something closer to 95 × 45 — so the board feet you order exceed the finished volume. Ask the supplier which convention their pricing uses before comparing two quotes.
Stairs, and where metric gets genuinely tricky
Stair geometry is the hardest conversion in building work, because both the rise and the going are code-controlled and neither can simply be scaled. A comfortable stair has a rise of about 180 to 190 millimetres and a going of at least 250 to 280 millimetres, and the relationship between them, not the total height, is what determines whether it feels right.
Given a total floor-to-floor height, divide by the rise to get the number of risers, then set the going from the code or from comfort. A 2.7 metre height with a 180 millimetre rise gives fifteen risers, and a 260 millimetre going gives a total run of about 3.6 metres for a floor space that must accommodate both.
Run your own numbers
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Common questions
How many board feet are in a cubic metre?
About 423. One cubic metre equals roughly 423 board feet, since one board foot is 0.00236 cubic metres.
What is the metric equivalent of a 2x4 stud wall?
A nominal 2 × 4 inch becomes about 100 × 50 mm in metric framing, with 40 cm or 60 cm stud centres. A 4.8 metre wall at 40 cm centres needs 13 studs.
Should I order metric or imperial timber?
Whichever your local supplier stocks in the sizes your project needs. Metric regions generally produce metric sizes, and timber is difficult to substitute across systems because of the nominal-versus-finished size difference.
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