Conversions between the different units of measure across imperial and metric systems using the formulae will lead to small rounding differences which are generally accepted by most buyers and sellers of timber products.
The basis of all conversions is based on 1” (inch) = 25.4 mm.
1 bf (board foot)= 1” x 12” x 12”
1 f3 (cubic foot) = 12” x 12” x 12” = 12 bf
1 mbf = 1000bf = 2.3597 m3 (cubic metres)
1 m3 = 423.776 bf = 35.3147 f3
1 Ton = 50 f3 = 600bdft = 1.416 m3 (Tons are used in Malaysia – a Ton is not a Weight Ton)
Sometimes trade is done with nominal measure volumes and prices. Net Measure is based on the actual dimensions of a timber product after machining. Nominal measure is based on the standard sizes of sawn timber (lumber) used to manufacture a machined product. For example in Decking a 1” x 6” nominal measure is used for decking machined to ¾” x 5.1/2” net size. In order to avoid pricing errors/ misunderstandings we recommend that trade for machined products is done in net measure only or with prices per linear foot or metre.
Linear metres (lm), linear feet (lf) and Yards (y)
1 y = 36” = 3ft = 914.4 mm
1 lm = 1000 mm = 39.37” = 3.2808 ft
1 ft = 12” = 304.8 mm =0.3048 m = 0.3333 y
Square feet (f2) or Square Metres (m2)
Some timber products like flooring are generally sold by area covered (excluding the tongue) rather than volume.
1 m2 = 10.7639 f2
1 f2 = 0.0929 m2