Board Foot Calculator
Board feet are how hardwood dealers and sawmills price lumber: a measure of volume, not length or area, equal to one square foot of wood an inch thick. This calculator runs two jobs from one screen -- a milled-lumber tally from thickness, width, length, and piece count, and a standing-log estimate that compares the Doyle, Scribner Decimal C, and International 1/4-inch rules. Add a price per board foot when you want an estimated order cost, or leave it blank for the volume alone.
Get the board-foot count right before you price it
Most people reach this tool to answer one of two questions: how many board feet am I buying, or how much might this log yield. The answer is only as good as the numbers you feed it, so the checks below cover the mode, the dimension basis, and the unit each field expects before you trust the total or hand a price to a supplier.
Stay in milled-lumber mode for cut boards. Switch to standing-log mode only when you are scaling a raw log and want the Doyle, Scribner, and International estimates.
Enter rough thickness for hardwood priced rough (4/4 is one inch). For a dressed 2x4, enter the actual 1.5 by 3.5 inches, not 2 by 4.
Thickness and width accept in, mm, or cm and length accepts ft, in, or m, so you can enter metric stock without converting first.
Leave price per board foot blank for the volume alone. Fill it in only once you trust the board-foot total and want an estimated order cost.
Example: a 12-board cherry order
A woodworker orders twelve pieces of 4/4 rough cherry, each 6 inches wide and 8 feet long, in milled-lumber mode. One board is (1 x 6 x 8) / 12 = 4 board feet, so twelve pieces total 12 x 4 = 48 board feet. Enter the yard's $7.25 per board foot and the estimate reads 48 x 7.25 = $348.00, before any tax, freight, or grade premium the yard adds on top.
Milled lumber vs standing log
Milled-lumber mode is the default and fits almost every buying task: enter thickness, width, length, and how many identical pieces you are tallying. Switch to standing-log mode only when you are scaling a raw log rather than a cut board. That mode swaps the thickness and width fields for a single small-end diameter and reports three separate yield estimates instead of one exact volume.
Nominal, rough, or dressed size?
Enter the dimensions that match how the wood is priced. Hardwood sold rough is measured at its rough thickness, often written in quarter notation where 4/4 is one inch, 5/4 is one and a quarter, and 8/4 is two inches. A dressed 2x4 from a home center actually measures 1.5 by 3.5 inches after surfacing, so enter those numbers, not 2 by 4, when you want its true volume.
Why the three log rules disagree
The standing-log estimates are not interchangeable. Doyle tends to under-report small logs because its formula subtracts a fixed slab allowance, Scribner Decimal C stays conservative on large logs, and the International 1/4-inch rule usually lands closest to real saw yield. Treat the spread as a range, not a guarantee -- none of the rules account for grade, taper, or how a given mill actually breaks the log down.
Board feet, linear feet, and square feet
These three units answer different questions. Board feet measure volume, so thickness and width both matter; linear feet measure running length only; square feet measure area. A one-inch by six-inch board holds 0.5 board feet per linear foot, and to convert square footage of a finished surface you multiply the area by the thickness in inches and divide by 12. Compare the output that matches the unit your supplier quotes.
When to switch calculators
This page prices one repeated board size or a single log. When you need a waste allowance, per-piece rounding, and a full buy list rather than a single board-foot figure, the Lumber Calculator handles the order tally and keeps board-foot, lineal-foot, and per-piece pricing side by side so you do not mix a volume total with a piece price.