Calculate board feet of lumber from thickness, width, and length for woodworking projects.
A board foot is the volume unit the hardwood trade bills in: 144 cubic inches, the size of a board 12 inches wide, 1 inch thick, and 1 foot long. This tool takes thickness, width, and length in the units you have - inches, feet, or quarter designations like 6/4 - converts everything to cubic inches, and divides by 144. The thing that trips up first-time buyers is that lumber dimensions are not what the labels say: a yard's 2x4 measures 1.5 by 3.5 inches, and hardwood thickness is quoted in quarters, so the answer is only as good as the numbers you type.
A concrete input and expected output from the current implementation.
Input
Thickness: 4/4 (1 in), width: 6 in, length: 8 ft
Expected output
4 board feet
A 1-inch by 6-inch cross-section is 6 square inches, and 8 feet is 96 inches, so the board is 576 cubic inches; dividing by 144 gives 4 board feet. The same result comes from (1 x 6 x 8) / 12 when length is in feet.
The tool converts thickness, width, and length to inches, multiplies the three to get cubic inches, then divides by 144. When you enter length in feet, that division collapses to (thickness x width x length in feet) / 12. Either path lands on the same number: a 1-inch by 12-inch board is exactly 1 board foot per foot of length.
Lumber dimensions arrive in three dialects: fractional inches, quarter designations such as 6/4 for 1.5 inches, and nominal softwood sizes where a 2x4 actually measures 1.5 by 3.5 inches. Feeding the tool nominal numbers instead of actual ones inflates the result by about half for a 2x4. The tool computes from whatever numbers you type, so converting to true dimensions first is on you.
A linear foot is just length; a board foot is volume. A 6-foot board that is 1 inch thick and 6 inches wide contains 3 board feet, because each foot of length holds half a board foot. For 1-inch stock, board feet per linear foot equals the width in inches divided by 12; for thicker stock, multiply that by the thickness in inches.
Usually one of three things: you used nominal dimensions where they measured actual, the yard quoted rough thickness while you calculated the planed size, or each board was rounded before the boards were added together. Hardwood is commonly priced by rough board footage, so planed stock still bills as a full inch. Ask how the yard measures before you compare totals.
The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.
Create customizable checklists with groups, due dates, and priorities for any project.
Design a printable daily planner with time blocks, goals, and priority sections.
Measure your typing speed in WPM and accuracy with real-time feedback and stats.
Pomodoro timer with built-in ambient noise (rain, cafe, forest) generated via Web Audio API oscillators.
Stay focused with a customizable Pomodoro timer featuring work and break intervals.
A precise stopwatch with lap tracking, split times, and exportable results.