ThisCalculator

Construction

Board Feet Calculator

Updated · Standard formula, shown below

Board feet per board 8.00 bd ft
Total board feet
80.00 bd ft
Result
Total volume
0.1888 m³
Result
Thickness
2 in
You entered

This calculator works out how many board feet are in a piece of lumber and in a stack of identical boards. Enter the thickness and width in inches, the length in feet and the number of boards.

Formula

One board foot is 1 in × 12 in × 12 in = 144 cubic inches. With length in feet: board feet = thickness (in) × width (in) × length (ft) ÷ 12. One board foot = 0.0023597 m³.

  • t: thickness in inches
  • w: width in inches
  • l: length in feet
  • n: number of identical boards

Worked Example

Ten boards, 2 in × 6 in, 8 ft long.

  1. 2 × 6 × 8 = 96; 96 ÷ 12 = 8.00 board feet per board
  2. 8 × 10 = 80.00 board feet in total
  3. 80 × 0.0023597 = 0.1888 m³

Limits and common mistakes

  • Hardwood is usually sold by nominal (rough) thickness, such as 4/4 = 1 in. A planed 2×6 actually measures about 1.5 × 5.5 in, so enter the size the seller prices by.
  • If the length is in inches, divide it by 12 first, or use thickness × width × length (all in inches) ÷ 144.
  • Add a waste allowance (often 10-20%) for defects and offcuts.
Formula used
in t | Thickness | in | 2 | 0
in w | Width | in | 6 | 0
in l | Length | ft | 8 | 0
in n | Number of boards | boards | 10 | 0
out bf | Board feet per board | bd ft | t * w * l / 12 | 2
out tot | Total board feet | bd ft | bf * n | 2
out m3 | Total volume | m³ | tot * 0.002359737216 | 4

Each line is one input (in, sel, list) or one result (out: label, unit, formula, decimals). How the calculators work

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.