The board foot is a unit of volume derived from the imperial system of units with the symbol FBM.
1 board foot is equal to the volume of an object one foot in length, one foot wide and one inch thick. It is therefore equal to 1/12 ft³.
The board foot is the unit used to measure rough or planed lumber. For example 2 x 4 timber when planed actually only measures 1.5 in x 3.5 in. This takes into account the wastage when planing. The board feet measurement in this case would represent the wholesale amount. Where the loss in board feet (and planing) only applies to width and thickness, the actual length is used - as there is no loss when cutting lengths.
The cubic millimetre (or cubic millimeter; US spelling) is a unit of volume and is derived from an SI unit with the symbol mm³.
One cubic millimetre is defined as the volume of a cube with sides one millimetre in length. It is the same as a microlitre. It is equal to 0.000000001m³.
There are 1 billion cubic millimetres in a cubic metre.