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Board Feet Calculator

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Enter a board's dimensions to find its board footage - the standard unit lumber is priced by, especially for hardwood and specialty lumber.

Board Feet Calculator

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Board feet
4.00
Board feet is a volume measurement, unlike linear feet - always use nominal (rough-cut) dimensions unless your supplier specifies otherwise.

The formula

Board feet = (Length in feet x Width in inches x Thickness in inches) / 12
Example

A single board 8 ft long, 6 inches wide, 1 inch thick: (8 x 6 x 1) / 12 = 4.00 board feet.

Step-by-step guide

  1. Enter the board's length in feet, and width and thickness in inches.
  2. Enter the quantity if you're calculating for multiple identical boards.
  3. Read the total board footage, which many lumber suppliers use directly for pricing.

Board feet vs. linear feet

Linear feet just measures length, ignoring width and thickness entirely - a 1x4 and a 2x12 of the same length have the same linear footage but very different amounts of actual wood. Board feet accounts for all three dimensions, making it a true volume measurement - this is why hardwood and specialty lumber (which vary more in width and thickness) is typically priced by the board foot, while standard dimensional softwood lumber (like a 2x4) is often simply priced by the linear foot or by the piece, since its cross-section is standardized.

Common mistakes

Using actual (finished, planed) dimensions instead of nominal dimensions - a "1 inch thick" board is often sold and priced based on its nominal size, even though the actual planed thickness is somewhat less (commonly around 13/16 inch after milling).
Mixing up width and thickness - board feet is sensitive to both, and swapping them by mistake gives a very different (and wrong) result for a non-square cross-section.

Frequently asked questions

Should I use nominal or actual lumber dimensions?

For pricing purposes, most hardwood suppliers calculate board feet using nominal (rough-cut, pre-planing) dimensions, even though the actual delivered board is slightly smaller after milling. Confirm which convention your specific supplier uses.

Why isn't a 2x4 priced by the board foot?

Standard dimensional softwood lumber has such consistent, predictable cross-sections that pricing per linear foot or per piece is simpler for both suppliers and buyers - board feet becomes more useful for lumber with varying widths and thicknesses, like hardwood.

Does this account for waste from planing or cutting?

No - this calculates the raw board footage of the dimensions entered. For a project with a lot of cutting and joinery waste, many woodworkers add 15-20% extra to their raw material order.

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