Board feet vs linear feet: buying lumber without overpaying
The difference between board feet and linear feet, how nominal sizes affect the math, and how to budget a hardwood order with waste built in.
Two very different units
Linear feet measure only length, ignoring how wide or thick a board is. Board feet measure volume, folding thickness, width and length into one number. A softwood shelf might be sold by the linear foot, while rough hardwood is almost always sold by the board foot because thicker, wider stock genuinely contains more wood. Confusing the two is the fastest way to misjudge a lumber budget, since a wide 8/4 board holds far more material per foot of length than a thin narrow one.
How nominal sizes change the number
Dimensional softwood carries a nominal label that is larger than the milled reality. A 2x4 is actually about 1.5 by 3.5 inches after it is dried and planed, yet board foot pricing uses the nominal 2 by 4. Rough sawn hardwood is different: it is often sold close to its true rough thickness in quarters, such as 4/4 or 8/4, and you pay for that rough volume even though final planing removes some. Knowing which convention your supplier uses keeps your estimate honest.
Turning board feet into a budget
Once you have total board feet, multiply by the price per board foot to get a materials cost, which is exactly what this calculator does. Hardwood prices vary widely by species, from inexpensive poplar to premium walnut, so update the price field for each wood. Remember that the sticker price is usually for rough lumber, and surfacing on four sides or to a finished thickness often costs more per board foot. Build that into your figure before committing to a species.
Always order more than the plan
A cut list tells you the finished board feet, but you can never buy exactly that. Boards arrive with knots, checks, splits and warp that must be cut around, and every crosscut and rip loses a saw kerf. Most woodworkers add 15 to 30 percent on top of the theoretical need, leaning toward the higher end for figured or defect prone stock. Because this tool reports exact volume, inflate the quantity yourself so the total board feet already carry that safety margin.