SqftKit · Lumber

Board foot calculator

Actual inches, not the nominal name of the board

A board foot is a volume: 12 inches by 12 inches by 1 inch thick. Lumber is often named by a nominal size, such as 2×6, that is larger than the board you can measure. This calculator uses the thickness and width you measure, in inches, and the length in feet.

Inputs

Result

Fill in the fields and press Calculate.

Disclaimer: Volume from the actual sizes you measure. The nominal stamp on the board is not used.

How to use

  1. Count the boards of this one size.
  2. Measure thickness and width in inches. A board sold as 2×6 is often about 1.5 by 5.5 inches. Measure yours.
  3. Enter the length in feet.
  4. Press Calculate. The hero is the total board feet. Each board is listed beside it.

How it's calculated

Board feet for one board = thickness × width × length ÷ 12, with thickness and width in inches and length in feet.

The total multiplies by the count. Nominal names are not converted. If you type 2 and 6, you are saying the board really is 2 inches by 6 inches.

Worked example

Ten boards that measure 1.5 inches by 5.5 inches by 8 feet: one board is 1.5 × 5.5 × 8 ÷ 12 = 5.5 board feet. Ten boards are 55 board feet. Typing the nominal 2 by 6 instead would overstate the volume.

Assumptions

Uniform boards. Wane, taper, and a price per board foot are not applied. Plywood sheets are a different unit and have their own page.

FAQ

Should I use nominal or actual size?

Actual. Board-foot pricing is a volume. The nominal name is a grade label, not the measurement.

What if the length is in inches?

Divide inches by 12 and enter feet. Eight feet is 96 inches.

Does this price the lumber?

No. Multiply the board feet by the price you were quoted.

Is a board foot the same as a square foot?

No. A square foot has no thickness. A board foot is one square foot, one inch thick.

Related tools