Board Foot Calculator Formula

Understand the math behind the board foot calculator. Each variable explained with a worked example.

Formulas Used

Board Feet (per board)

bf_per_board = thickness * width * length_ft / 12

Total Board Feet

total_bf = thickness * width * length_ft / 12 * quantity

Variables

VariableDescriptionDefault
thicknessThickness(inches)2
widthWidth(inches)8
length_ftLength(feet)10
quantityNumber of Boards1

How It Works

How to Calculate Board Feet

Formula

Board Feet = (Thickness in inches × Width in inches × Length in feet) / 12

One board foot equals 144 cubic inches of wood. This is the standard measurement for buying and selling hardwood lumber. Thickness and width are in inches, length is in feet.

Worked Example

A single board 2 inches thick, 8 inches wide, 10 feet long.

thickness = 2width = 8length_ft = 10quantity = 1
  1. 01Board feet = (2 × 8 × 10) / 12 = 160 / 12 = 13.33 BF

Ready to run the numbers?

Open Board Foot Calculator