Board Foot Calculator
Turn a repeatable lumber size and piece count into board feet without confusing nominal labels, actual dimensions, or log-scaling rules.
- Board feet per piece
- 12
- Number of boards
- 10
- Total board feet
- 120
- Physical cubic volume
- 10 ft³
Use the dimensions on which the lumber is tallied. Nominal and actual dimensions produce different physical volumes.
Show calculation
2 in × 6 in × 12 ft ÷ 12 × 10 boards = 120 board feetTransparent method and editable product assumptions. Verify current labels and project requirements.
How this calculator works
One board foot is a volume of 144 cubic inches: one inch thick by twelve inches wide by twelve inches long. With thickness and width in inches and length in feet, divide their product by 12, then multiply by the number of boards.
Use the measurement basis that controls the transaction. Softwood lumber may be tallied from nominal thickness and width with actual length, while a physical-volume check uses actual dimensions. This calculator never silently switches between nominal and dressed sizes.
This is a rectangular sawn-lumber calculator, not a log board-foot rule. Doyle, Scribner, and International log rules estimate recoverable lumber from round logs and can produce different results because they incorporate separate assumptions.
Formula
Board feet = thickness (in) × width (in) × length (ft) ÷ 12 × quantityThe live substitution appears with your result.Control example: ten 2 × 6 × 12 ft boards
One nominal 2 × 6 × 12 ft board contains 2 × 6 × 12 ÷ 12 = 12 board feet.
Ten boards contain 120 board feet, equivalent to 10 ft³ of nominal rectangular volume.
Assumptions and limits
- Every board in the batch has the entered dimensions.
- Thickness and width use one consistent nominal or actual basis.
- Length is the physical board length.
- The quantity is a whole number of rectangular boards.
Common measuring mistakes
- Mixing nominal thickness with actual width.
- Entering length in inches when the field expects feet.
- Dividing by 144 while length is already in feet.
- Using the rectangular lumber formula to scale logs or standing trees.
Sources
Product-specific values remain editable. These sources support the method and stated examples; they are not a universal substitute for your supplier’s current label.
- Penn State Extension: Valuing Standing Timber Defines a board foot as 144 in³ and publishes the thickness × width × length ÷ 12 formula for sawn lumber.
- American Wood Council metric lumber guidance Provides the board-foot to cubic-meter conversion used for the metric volume cross-check.
Questions people ask
What is a board foot?
It is 144 cubic inches of wood, equivalent to a board 1 inch thick, 12 inches wide, and 12 inches long.
How do I calculate board feet?
Multiply thickness in inches by width in inches by length in feet, divide by 12, and multiply by quantity.
Should I use nominal or actual lumber dimensions?
Use the basis that controls your tally or quote, and keep thickness and width consistent. Actual dimensions are better for physical volume.
Is a board foot the same as a square foot?
No. A board foot is volume; a square foot is area. Board thickness is part of the calculation.
Can this calculate board feet in a log?
No. Logs require a named scaling rule such as Doyle, Scribner, or International and are intentionally outside this rectangular-lumber page.