Board foot


The board foot or board-foot is a unit of measurement for the volume of lumber in the United States and Canada. It is the volume of a one-foot length of a board one foot wide and one inch thick.
Board foot can be abbreviated FBM, BDFT, or BF. Thousand board feet can be abbreviated as MFBM, MBFT, or MBF. Similarly, million board feet can be abbreviated as MMFBM, MMBFT, or MMBF.
In Australia and New Zealand the term super foot or superficial foot was used to mean the same.
One board foot equals:
Board foot is the unit of measure for rough lumber or planed/surfaced lumber. An example of planed lumber is softwood 2 × 4 lumber one would buy at a large lumber retailer. The 2 × 4 is actually only but the dimensions for the lumber when purchased wholesale could still be represented as full 2 × 4 lumber, although the "standard" can vary between vendors. This means that nominal lumber includes air space around the physical board when calculating board feet in some situations, while the true measurement of "board feet" should be limited to the actual dimensions of the board.
For planed lumber, board feet refer to the nominal thickness and width of lumber, calculated in principle on its size before drying and planing. Actual length is used.
See dimensional lumber for a full discussion of the relationship of actual and nominal dimensions. Briefly, for softwoods, to convert nominal to actual, subtract for dimensions under 2″; subtract for dimensions over 2″ and under 8″; and subtract for larger measurements. The system is more complicated for hardwoods.
An Essex table is a tabulation of the number of board feet in lumber of varying dimensions.