Board Foot Calculator
Lumber volume and cost from nominal sizes, piece by piece.
Lumber list (nominal sizes)
= 144" (12')
= 192" (16')
Results update as you typeLive
Board Feet · Result
CalculatedBOARD FEET
464.00 board feet
- Net board feet
- 464.00
- Waste
- 0%
- Pieces
- 2
- Cost
- $2088.00
Code references & assumptions · 1
How this result is supported
- CODE REFERENCEBoard feet use nominal thickness and width with the actual length (7 CFR 1217.4, for softwood 1 in or more thick); a nominal 2x4 is measured as 2 by 4, not 1.5 by 3.5
- PRIMARY-VERIFIED
What do these evidence labels mean?
- PRIMARY-VERIFIED
- directly supported by one authoritative primary source, quoted with section/page/figure
- CROSS-VERIFIED
- independently supported by two or more appropriate authoritative sources
- DERIVED
- mathematically derived from PRIMARY-VERIFIED values; the derivation is preserved in data and in code
- INTERPRETED
- a source exists but translating it into calculator behaviour required interpretation
- CONVENTION
- recognised trade practice, not a mandatory provision
- ASSUMPTION
- product/design assumption or useful default with no authoritative basis
- UNVERIFIED
- insufficient authoritative evidence
Code references and product data are quoted in the units their source uses.
Reference checks are informational, not compliance determinations.
How board foot is calculated
A board foot is the volume of a piece one inch thick, twelve inches wide and one foot long. Every lumber list is priced in them, which is why the unit survives despite describing a board almost nobody buys.
Sizes here are NOMINAL — the size lumber is sold as, not the size it measures. A 2×8 is nominally 2 by 8 and actually 1½ by 7¼, and board feet are computed on the nominal figure because that is what the yard charges for. Quarter sizes go in as decimals: 4/4 is 1, 5/4 is 1.25, 8/4 is 2.
Each entry carries its own count, so twelve identical joists are one line rather than twelve, and the line still shows what one of them comes to.
board feet = thickness × width × length ÷ 12
Thickness and width in nominal inches, length in feet.
total = Σ (board feet × count)