How To Calculate Board Feet
Board Foot Calculator

Fill In Your Dimensions:

Decimals or fractions okay
Decimals or fractions okay


FYI: The running total adds the board footage of multiple boards. Simply compute one board at a time at left.

Your Attention, Please:

  1. Only use numbers, and convert your dimensions to inches (not feet). Do not input quotes (" or ')
  2. Both slashes ( / ) or periods ( . ) are acceptable for fractional sizes
  3. Thickness can be tricky, sorry to say:
    • This calculator rounds fractional thicknesses up to the nearest 1/4" - i.e. 3/4" will convert to 1" (or 4/4) because that's the size of lumber you'll need to start with in order to finish at 3/4"
    • Thicknesses less than 1" are custom milled from 4/4 material and sold by the square foot, therefore this calculator will convert thicknesses less than 1" to 1" for the sake of calculation

What's a board foot, anyway?

A board foot (bd. ft.) is the unit of measurement for hardwood lumber 1" or thicker

It's Just an Estimation, BTW

Board footage helps you make an educated guess as to how much lumber you'll need. Afterall, you'll be cutting and/or gluing your project parts from boards of various sizes.

Always plan to buy extra to make sure you're covered to cut out your parts, glue up to width, arrange grain patterns and color, fix mistakes, make test cuts on joinery set-ups, and test finishes.

Video: How To Plan a Project

The Board Foot Formula

3 Methods
Same Result

T" x W" x L" ÷ 144 = Bd. Ft.


T" x W" x L' ÷ 12 = Bd. Ft.


T" x Sq. Ft. = Bd. Ft.

Your Attention, Please:

1 Bd. Ft. = 144 cubic inches

Thickness uses the rough sawn dimension, not your final net dimension

Board footage is the measurement when buying random widths and random lengths. To determine what to buy, convert your project parts into board footage and use that to estimate about how much you'll need to buy.

FYI: lumber under 1" is calculated and expressed in square feet

board footage calculation

When you're looking at a stack of hardwood lumber and and you begin picking out the boards you like and want to buy, you'll notice that each board has a different width (W), and possibly a different length (L).

Let's say you've found two pieces in the 4/4 stack, one is 8" x 96" and the other is 4" x 96". Should you pay the same price for both pieces just because they're the same length?

Of course not. The first board has twice the amount of wood in it (it's twice as wide and the same length).

The unit of measurement for this kind of lumber, then, is the board foot. It's a measure of the volume of wood that's in a board.