Materials take-off
how much materialestimating quantitiesordering formulas
Board feet, sheets, studs, paint, concrete bags and truck loads — turning drawings into an order list.
Board Feet of Lumber
The lumberyard's volume unit: thickness in inches times width in inches times length in feet, divided by twelve. One board foot is 144 cubic inches.
Sheets or Tiles Needed (with Waste Allowance)
Counts the sheets, tiles or planks a surface takes: the area to cover, padded by a percent waste allowance for cuts and breakage, divided by the area one unit covers.
Studs on a Wall at a Given Spacing
Counts the studs, joists or fence posts along a run at a fixed on-centre spacing, including the one that closes the far end.
Paint Quantity from Coverage Rate
Containers of paint needed: the surface area times the number of coats, divided by the area one container covers at the manufacturer's spread rate.
Concrete Bags from Volume and Bag Yield
Counts bags of premixed concrete: the volume of the pour divided by the yield printed on the bag, typically 0.6 ft³ for an 80 lb bag or 13.5 L for a 30 kg bag.
Truck Loads from Bank Volume and Swell
Turns an in-place excavation quantity into truck loads: bank volume swelled to its loose volume, divided by the capacity of one truck box.
Pieces from a Stock Length (with Saw Kerf)
How many finished pieces come out of one stock length once every cut eats a kerf of saw blade. The last piece needs no trailing kerf, which is where the +k on top comes from.
How they fit together
Take-off is the arithmetic between a drawing and a purchase order, and it has one universal rule that no formula can express: round in the direction that keeps you working. Sheets, studs, bags and truck loads all round up, because a short order stops the job. Pieces cut from stock round down, because the remainder is offcut rather than product.
The solvers here return the exact figure rather than the rounded one, deliberately. A stud count of 13.4 tells you something a 14 does not: that you are barely over, and that nudging the wall length or the spacing might save a piece. Rounding is a decision, so it stays with the person making it.
Board feet deserves its own note, because it is the one unit that surprises people: it measures volume, not length or area. A board foot is 144 cubic inches, so a 2x10 twelve feet long is exactly 20 board feet regardless of how it is cut up.